Air curtain generation for environmental control in automated data storage libraries

ABSTRACT

A data storage library includes an array of drive slots each configured to receive a data storage drive therein. The data storage library also includes a nozzle for creating an air curtain across a front of the array of drive slots and a fan for creating an airflow through the nozzle. A method includes selectively instructing a fan to create an airflow through a nozzle for creating an air curtain across a front of an array of drive slots in the data storage library. A computer program product is configured to perform the foregoing method.

BACKGROUND

The present invention relates to data storage systems, and moreparticularly, this invention relates to an air curtain system forenvironmental control in automated data storage libraries.

Automated data storage libraries are known for providing cost effectivestorage and retrieval of large quantities of data. The data in automateddata storage libraries is typically stored on media of data storagecartridges that are, in turn, stored at storage slots or the like insidethe library in a fashion that renders the media, and its resident data,accessible for physical retrieval. Such data storage cartridges arecommonly termed “removable media.” Data storage cartridge media maycomprise any type of media on which data may be stored and which mayserve as removable media, including but not limited to magnetic media(such as magnetic tape or disks), optical media (such as optical tape ordiscs), electronic media (such as PROM, EEPROM, flash PROM,CompactFlash™, Smartmedia™, Memory Stick™, etc.), or other suitablemedia. An example of a data storage cartridge that is widely employed inautomated data storage libraries for mass data storage is a magnetictape cartridge.

In addition to data storage media, automated data storage librariestypically comprise data storage drives that store data to, and/orretrieve data from, the data storage cartridge media. Further, automateddata storage libraries typically comprise I/O stations at which datastorage cartridges are supplied or added to, or removed from, thelibrary. The transport of data storage cartridges between data storageslots, data storage drives, and I/O stations is typically accomplishedby one or more accessors. Such accessors have grippers for physicallyretrieving the selected data storage cartridges from the storage slotswithin the automated data storage library and transporting suchcartridges to the data storage drives by moving, for example, in thehorizontal (X) and vertical (Y) directions.

In an effort to increase storage capacity, deep slot technology allowsfor storage cells that contain more than a single data storagecartridge. Such storage libraries allow for higher density, or morecartridges stored per square foot. In ‘deep slot’ libraries, two or morecartridges may be stored in a multi-cartridge deep slot cell, arrayed inseries, one behind the other, in tiers ranging from a frontmost tier toa rearmost tier.

Data centers with free-cooling facility environments have wider rangesof temperature and relative humidity than traditional data centers withdedicated computer room air conditioners (CRACs). While servers anddisk-based storage equipment may be able to operate within these widerranges, tape storage equipment cannot operate reliably in the extremelimits of these conditions. Self-cooling libraries include automatedtape libraries that are appropriately sealed and fitted with integralair conditioning. Self-cooling libraries control the temperature and therelative humidity of the environment in the library so that thecontained tape drives and tape media operating conditions areacceptable.

Problems occur when a data storage library door is opened for operatorand/or service access. When a library door is opened, unsafe, outsideair may enter the enclosure. Data storage media and/or data storageequipment may be damaged if the ambient temperature and/or the relativehumidity of the air entering the enclosure is outside the safe and/orfunctional operating limits of the data storage media and/or datastorage equipment.

In a self-cooling library, when the ambient temperature and/or relativehumidity of the data center becomes warm and moist (e.g. at atemperature of 35 degrees Celsius and 80% relative humidity), the tapedrives inside the library may have an internal temperature ofapproximately 25 degrees Celsius. This internal temperature is below thedew point temperature of the outside air. If the internal temperature isbelow the dew point temperature of the outside air, in response toopening the front door of the library, the outside air may enter thetape drive and water vapor may condense on the tape drive read/writehead element and/or other sensitive elements. Condensation may result inpermanent damage, e.g., corrosion, to the tape drive read/write headelement and/or other sensitive elements.

The tape drives in a self-cooling library are housed in tape drivecanister assemblies that include cooling fans that draw air from thefront of the tape drive canister and exhaust air out of the back of thetape drive canister. The front of the tape drive canister typicallyfaces the door of the library enclosure so that the tape drive canistercooling fans actively pull the warm and moist air through the tapedrive. This active pulling of warm and moist air through the tape driveincreases the probability that condensation occurs in the tape drive.

Another problem that may arise in a self-cooling library involvesinadequate internal air mixing. Inadequate internal air mixing maycreate warm and cold regions in the library. The warm and cold regionsin the library may result in tape drives maintained at varying operatingtemperatures. Different operating temperatures in the library may resultin undesirable variations in the long-term reliability of the tapedrives and may reduce the probability that all tapes may be read on alldrives.

A prior attempt to address condensation and air mixing issues includesimplementing an indicator on the front of the library that lights upwhen the tape drive internal temperature and relative humidity are suchthat condensation is possible. The indicator light warns that the doorshould not be opened at that time.

A drawback to this attempted approach is that the inside of the librarycannot be accessed when the indicator light is on and, therefore, anyoperator and/or service action is delayed until the environmentalconditions in the library change sufficiently to turn off the indicatorlight. This delay may be hours or days.

Further attempts to address condensation and/or air mixing issuesinclude putting tape drive canisters into a “self-protect mode.” In aself-protect mode, the cooling fans in the tape drive canister areturned off to prevent condensation by keeping warm and moist air fromentering the tape drives. The tape drive internal temperature rises whencooling fans in the tape drive canister are turned off. The increase inthe tape drive internal temperature decreases the probability that thesensitive head component is below the dew point temperature so thatcondensation is less likely to occur. However, the tape drive internalelectronics eventually reach the maximum operating temperature when thetape drive canister's cooling fans are turned off. In response toreaching the tape drive internal electronics' maximum operatingtemperature, the tape drive canister's cooling fans turn on for asufficient time to cool down the internal electronics. The tape drivecanister's cooling fans draw the moist, ambient air into the tape drive,but the head component is warmed to above the dew point temperature. Inresponse to the tape drive internal electronics cooling off, the tapedrive canister's cooling fans turn off. The tape drive canisters in aself-protect mode continue this on-off cycling as long as the tape drivecanisters are in self-protect mode.

A drawback to this attempted approach is that the self-protect mode maynot sufficiently prevent condensation on the head element if the tapedrive canister cooling fans are turned on before the internaltemperatures have risen to above the dew point of the outside air.

Moreover, the swings in temperature are more likely to cause thermaldegradation of the sensitive drive components. Additionally, repeatedlyraising and lowering the temperatures in the self-protect mode maycreate stress on the components and/or solder joints of the tape driveinternal electronics. Stress on the components and/or solder joints ofthe tape drive internal electronics may lower the long-term reliabilityof the tape drive.

SUMMARY

A data storage library according to one approach includes an array ofdrive slots each configured to receive a data storage drive therein. Thedata storage library also includes a nozzle for creating an air curtainacross a front of the array of drive slots and a fan for creating anairflow through the nozzle. The data storage library provides thebenefit of an air curtain which reduces the amount of warmer and/or morehumid outside air that reaches sensitive tape drive components locatedbehind the air curtain.

A data storage library may optionally include a cold air inlet formixing cooler air with air being move by the fan. The cold air inletprovides the benefit of supplying the library and the air curtain withrelatively cooler air in order to control the environment of the datastorage library.

A data storage library may optionally include data storage drives in atleast some of the drive slots. The data storage library may beconfigured to create a full air curtain across the entire front of theoccupied drive slots. The volume of air entering the air curtain is atleast as great as a volume of air the drives in the drive slotscumulatively draw. The full air curtain across the entire front of theoccupied drive slots may provide the benefit of a sufficient area andvolume of air such that the air curtain prevents intermixing of outsideair and air in the air curtain.

A method according to one approach includes selectively instructing afan to create an airflow through a nozzle for creating an air curtainacross a front of an array of drive slots in the data storage library.The method provides the benefit of an air curtain which serves as abarrier between outside air and sensitive tape drive components locatedbehind the air curtain.

The fan may optionally be instructed to run continuously when acontinuous mode is active. The fan may also and/or alternatively beinstructed to run in response to a trigger condition when arecirculating mode is active. The continuous mode provides the benefitof more constant environmental control within the data storage library.The recirculation mode provides the benefit of environmental controlwhich responds to a trigger condition such as opening of the datastorage library door, thereby saving power.

A method may optionally include instructing the fan to run continuouslyin a continuous mode. Cooler air is selectively added to air being movedby the fan for cooling the air based on at least one factor. The factormay be selected from the group consisting of: a temperature reading ofthe air and a humidity reading of the air. Selectively adding cooler airto air being moved by the fan for cooling the air provides the benefitof providing more control over the temperature and/or humidity withinthe data storage library.

A computer program product according to one approach is configured toperform the foregoing method.

Other aspects and approaches of the present invention will becomeapparent from the following detailed description, which, when taken inconjunction with the drawings, illustrate by way of example theprinciples of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of an automated data storage libraryaccording to one approach.

FIG. 2 is a perspective view of a storage frame from the data storagelibrary of FIG. 1.

FIG. 3 is a block diagram of an automated data storage library accordingto one approach.

FIG. 4 is a block diagram depicting a controller configuration accordingto one approach.

FIG. 5A is a front perspective view of a data storage drive according toone approach.

FIG. 5B is a rear perspective view of the data storage drive of FIG. 5A.

FIG. 6 is perspective view of a data storage cartridge having a cutawayportion, according to one approach.

FIGS. 7A-7B are perspective views of a multi-cartridge deep slot cellaccording to one approach.

FIGS. 8A-8D are partial side views of a cartridge blocking mechanismaccording to one approach.

FIG. 9 is a depiction of a tiered data storage system in accordance withone approach.

FIG. 10 is a perspective view of a data storage library with anintegrated cooling system according to one approach.

FIG. 11A is a front perspective view of a tape drive canister accordingto one approach.

FIG. 11B is a rear perspective view of the tape drive canister of FIG.11A according to one approach.

FIG. 12A is a front perspective view of an air curtain canisteraccording to one approach.

FIG. 12B is a rear perspective view of the air curtain canister of FIG.12A according to one approach.

FIG. 13 is a perspective view of the air curtain canister of FIG. 12Awith a cover removed, according to one approach.

FIG. 14A is a side view of an air curtain canister according to oneapproach.

FIG. 14B is a cross-sectional view of the air curtain canister of FIG.14A, according to one approach.

FIG. 15 is a partial cross-sectional side view of a storage frame of thedata storage library of FIG. 10 according to one approach.

FIG. 16 is a partial cross-sectional side view of a storage frame of thedata storage library of FIG. 10 according to one approach.

FIG. 17 is a partial cross-sectional side view of a storage frame of thedata storage library of FIG. 10 according to one approach.

FIG. 18 is a partial cross-sectional side view of a storage frame of thedata storage library of FIG. 10 according to one approach.

FIG. 19 is a partial cross-sectional side view of a storage frame of thedata storage library of FIG. 10 according to one approach.

FIG. 20 is a partial cross-sectional side view of a storage frame of thedata storage library of FIG. 10 according to one approach.

DETAILED DESCRIPTION

The following description is made for the purpose of illustrating thegeneral principles of the present invention and is not meant to limitthe inventive concepts claimed herein. Further, particular featuresdescribed herein can be used in combination with other describedfeatures in each of the various possible combinations and permutations.

Unless otherwise specifically defined herein, all terms are to be giventheir broadest possible interpretation including meanings implied fromthe specification as well as meanings understood by those skilled in theart and/or as defined in dictionaries, treatises, etc.

It must also be noted that, as used in the specification and theappended claims, the singular forms “a,” “an” and “the” include pluralreferents unless otherwise specified.

The following description discloses several preferred approaches of datastorage systems and apparatuses for creating air curtains, as well asoperation and/or component parts thereof.

In one general approach, a data storage library includes an array ofdrive slots each configured to receive a data storage drive therein. Thedata storage library also includes a nozzle for creating an air curtainacross a front of the array of drive slots and a fan for creating anairflow through the nozzle.

In another general approach, a method includes selectively instructing afan to create an airflow through a nozzle for creating an air curtainacross a front of an array of drive slots in the data storage library.The method provides the benefit of creating an air curtain which is abarrier for the tape drives in the data storage library from the outsideair.

In yet another general approach, computer program product is configuredto perform the foregoing method.

FIGS. 1-2 illustrate an automated data storage library 10 which storesand retrieves data storage cartridges, containing data storage media(not shown), from multi-cartridge deep slot cells 100 and singlecartridge storage slots 16. An example of an automated data storagelibrary which has a similar configuration as that depicted in FIGS. 1-2,and may be implemented with some of the various aspects herein is theIBM 3584 UltraScalable Tape Library. Moreover, it should be noted thatreferences to “data storage media” herein refer to data storagecartridges, and for purposes of the present application, the two termsmay be used synonymously.

The library 10 of FIG. 1 comprises a left hand service bay 13, one ormore storage frames 11, and right hand service bay 14. As will bediscussed in further detail below, a frame may comprise an expansioncomponent of the library. Thus, storage frames may be added or removedto expand or reduce the size and/or functionality of the library.According to different approaches, frames may include additional storageslots, deep slot cells, drives, import/export stations, accessors,operator panels, etc.

FIG. 2 shows an exemplary approach of a storage frame 11, which acts asthe base frame of the library 10. Moreover, the storage frame 11illustrated in FIG. 2 is contemplated to be a minimum configuration ofthe library 10, for which there is only a single accessor 18 (i.e.,there are no redundant accessors) and no service bay. However, in otherapproaches, a storage frame may include multiple robotic accessorsand/or service bays.

Looking to FIG. 2, the library 10 is arranged for accessing data storagemedia in response to commands from at least one external host system(not shown). The library 10 includes a plurality of storage slots 16 onfront wall 17 and a plurality of multi-cartridge deep slot cells 100 onrear wall 19, both of which may be used for storing data storagecartridges that may contain data storage media. According to oneapproach, the storage slots 16 are configured to store a single datastorage cartridge, and the multi-cartridge deep slot cells 100 areconfigured to store a plurality of data storage cartridges. In apreferred approach, the multi-cartridge deep slot cells may be arrangedin sequential order of tiers from front to rear (e.g., see FIG. 7A).

With continued reference to FIG. 2, the storage frame 11 of the library10 also includes at least one data storage drive 15, e.g., for readingand/or writing data with respect to the data storage media.Additionally, a first accessor 18 may be used to transport data storagemedia between the plurality of storage slots 16, the multi-cartridgedeep slot cells, and/or the data storage drive(s) 15. According tovarious aspects, the data storage drives 15 may be optical disc drives,magnetic tape drives, solid state drives having nonvolatile randomaccess memory (NVRAM) such as Flash memory, or other types of datastorage drives as are used to read and/or write data with respect to thedata storage media.

As illustrated, the storage frame 11 may optionally include an operatorpanel or other user interface, such as a web-based interface, whichallows a user to interact with the library 10. The storage frame 11 mayalso optionally comprise an upper I/O station 24 and/or a lower I/Ostation 25, thereby allowing data storage cartridges to be added (e.g.,inserted) to the library inventory and/or removed from the librarywithout disrupting library operation. Furthermore, the library 10 mayhave one or more storage frames 11, each having storage slots 16,preferably accessible by the first accessor 18.

As described above, the storage frames 11 may be configured withdifferent components depending upon the intended function. Oneconfiguration of storage frame 11 may comprise storage slots 16 and/ormulti-cartridge deep slot cells 100, data storage drive(s) 15, and otheroptional components to store and retrieve data from the data storagecartridges. However, in another approach, a storage frame 11 may includestorage slots 16 and/or multi-cartridge deep slot cells 100 and no othercomponents. The first accessor 18 may have a gripper assembly 20, e.g.,for gripping one or more data storage media, in addition to having a barcode scanner or other reading system, such as a cartridge memory readeror similar system mounted on the gripper assembly 20, to “read”identifying information about the data storage media.

FIG. 3 depicts an automated data storage library 10, in accordance withone approach. As an option, the present automated data storage library10 may be implemented in conjunction with features from any otherapproach listed herein, such as those described with reference to theother FIGS. Of course, however, such automated data storage library 10and others presented herein may be used in various applications and/orin permutations which may or may not be specifically described in theillustrative configurations listed herein. Further, the automated datastorage library 10 presented herein may be used in any desiredenvironment. Thus FIG. 3 (and the other FIGS.) should be deemed toinclude any and all possible permutations.

Referring now to FIG. 3, the automated data storage library 10 asdescribed in reference to FIGS. 1 and 2, is depicted according to oneapproach. According to a preferred approach, the library 10 may employ acontroller, e.g., arranged as a distributed system of modules with aplurality of processor nodes.

In one configuration, the library is controlled, not by a centralcontroller, but rather, by a distributed control system for receivinglogical commands and converting the commands to physical movements ofthe accessor and gripper, and for operating the drives in accordancewith the desired physical movements. The distributed control system mayalso provide logistical support, such as responding to host requests forelement status, inventory, library status, etc. The specific commands,the conversion of those commands to physical movements, and theoperation of the drives may be of a type known to those of skill in theart.

While the automated data storage library 10 has been described asemploying a distributed control system, various other approachesdescribed and/or suggested herein may be implemented in automated datastorage libraries regardless of control configuration, such as, but notlimited to, an automated data storage library having one or more librarycontrollers that are not distributed.

Referring still to FIG. 3, the library 10 may have one or more storageframes 11, a left hand service bay 13 and a right hand service bay 14.The left hand service bay 13 is shown with a first accessor 18, where,as discussed above, the first accessor 18 may include a gripper assembly20 and/or a bar code scanner (e.g., reading system) to “read”identifying information about the data storage media depending on thedesired approach. Furthermore, the right hand service bay 14 is shownhaving a second accessor 28, which includes a gripper assembly 30 andmay also include a reading system 32 to “read” identifying informationabout the data storage media.

According to one approach, in the event of a failure or otherunavailability of the first accessor 18, or its gripper assembly 20,etc., the second accessor 28 may perform some or all of the functions ofthe first accessor 18. Thus in different approaches, the two accessors18, 28 may share one or more mechanical paths, they may have completelyindependent mechanical paths, or combinations thereof. In one example,the accessors 18, 28 may have a common horizontal rail with independentvertical rails to travel therealong. Moreover, it should be noted thatthe first and second accessors 18, 28 are described as first and secondfor descriptive purposes only and this description is not meant to limiteither accessor to an association with either the left hand service bay13, or the right hand service bay 14.

In an exemplary approach which is in no way intended to limit theinvention, the first and second accessors 18, 28 may preferably movetheir grippers in at least two directions, called the horizontal “X”direction and vertical “Y” direction, e.g., to retrieve and grip,deliver and release, load and unload, etc. the data storage cartridge atthe storage slots 16, multi-cartridge deep slot cells 100, data storagedrives 15, etc.

With continued reference to FIG. 3, library 10 receives commands fromone or more host systems 40, 41, 42. The host systems 40, 41, 42, suchas host servers, communicate with the library directly, e.g., on path80, through one or more control ports (not shown), or through one ormore data storage drives 15 on paths 81, 82. Thus, in differentapproaches, the host systems 40, 41, 42 may provide commands to accessparticular data storage cartridges and move the cartridges, for example,between the storage slots 16 and the data storage drives 15. Thecommands are typically logical commands identifying the cartridges orcartridge media, and/or logical locations for accessing the media.Furthermore, it should be noted that the terms “commands” and “workrequests” are used interchangeably herein to refer to suchcommunications from the host system 40, 41, 42 to the library 10 as areintended to result in accessing particular data storage media within thelibrary 10 depending on the desired approach.

According to one approach, the library 10 may be controlled by a librarycontroller. Moreover, in various aspects, the library controller mayinclude a distributed control system receiving the logical commands fromhosts, determining the required actions, and/or converting the actionsto physical movements of the first and/or second accessor 18, 28. Inanother approach, the distributed control system may have a plurality ofprocessor nodes, each having one or more computer processors. Accordingto one example of a distributed control system, a communicationprocessor node 50 may be located in a storage frame 11. Thecommunication processor node provides a communication link for receivingthe host commands, either directly or through the drives 15, via atleast one external interface, e.g., coupled to line 80.

Still referring to FIG. 3, the communication processor node 50 mayadditionally provide a communication link 70 for communicating with thedata storage drives 15. As illustrated, the communication processor node50 may preferably be located in the storage frame 11, e.g., close to thedata storage drives 15. Furthermore, one or more additional workprocessor nodes may be provided to form an exemplary distributedprocessor system, which may comprise, e.g., a work processor node 52located at first accessor 18, and that is coupled to the communicationprocessor node 50 via a network 60, 157. According to differentapproaches, each work processor node may respond to received commandsthat are broadcast thereto from any communication processor node, andthe work processor nodes may also direct the operation of the accessors,e.g., providing move commands. An XY processor node 55 may be providedand may be located at an XY system of first accessor 18. As illustrated,the XY processor node 55 is coupled to the network 60, 157, and isresponsive to the move commands, operating the XY system to position thegripper assembly 20.

Also, an operator panel processor node 59 may be provided at theoptional operator panel for providing an interface for communicatingbetween the operator panel and the communication processor node 50, thework processor nodes 52, 252, and the XY processor nodes 55, 255.

A network 60, for example comprising a common bus, is provided, couplingthe various processor nodes. The network may comprise a robust wiringnetwork, such as the commercially available Controller Area Network(CAN) bus system, which is a multi-drop network, having a standardaccess protocol and wiring standards, for example, as defined by CiA,the CAN in Automation Association, Am Weich Selgarten 26, D-91058Erlangen, Germany. Other networks, such as Ethernet, or a wirelessnetwork system, such as RF or infrared, may be employed in the libraryas is known to those of skill in the art. In addition, multipleindependent networks may also be used to couple the various processornodes.

As illustrated in FIG. 3, the communication processor node 50 is coupledto each of the data storage drives 15 of a storage frame 11, via lines70, and are thereby communicating with the drives 15 and with hostsystems 40, 41, 42. Alternatively, the host systems 40, 41, 42 may bedirectly coupled to the communication processor node 50, at input 80 forexample, or to control port devices (not shown) which connect thelibrary to the host system(s) with a library interface similar to thedrive/library interface. As is known to those of skill in the art,various communication arrangements may be employed for communicationwith the hosts and with the data storage drives. In the example of FIG.3, host connections 80 and 81 are intended to be Ethernet and a SCSIbus, respectively, e.g., and may serve as host connections. However, bus82 comprises an example of a Fibre Channel bus which is a high speedserial data interface, allowing transmission over greater distances thanthe SCSI bus systems.

According to some approaches, the data storage drives 15 may be in closeproximity to the communication processor node 50, and may employ a shortdistance communication scheme, such as Ethernet, or a serial connection,such as RS-422. Thus the data storage drives 15 may be individuallycoupled to the communication processor node 50 by lines 70.Alternatively, the data storage drives 15 may be coupled to thecommunication processor node 50 through one or more networks.

Furthermore, additional storage frames 11 may be provided, whereby eachis preferably coupled to the adjacent storage frame. According tovarious aspects, any of the additional storage frames 11 may includecommunication processor nodes 50, storage slots 16, data storage drives15, networks 60, etc.

Moreover, as described above, the automated data storage library 10 maycomprise a plurality of accessors. A second accessor 28, for example, isshown in a right hand service bay 14 of FIG. 3. The second accessor 28may include a gripper assembly 30 for accessing the data storage media,and an XY system 255 for moving the second accessor 28. The secondaccessor 28 may run on the same horizontal mechanical path as the firstaccessor 18, and/or on an adjacent (e.g., separate) path. Moreover theillustrative control system additionally includes an extension network200 which forms a network coupled to network 60 of the storage frame(s)11 and to network 157 of left hand service bay 13.

In FIG. 3 and the accompanying description, the first and secondaccessors are associated with the left hand service bay 13 and the righthand service bay 14 respectively. However, this is for illustrativepurposes and there may not be an actual association. Thus, according toanother approach, network 157 may not be associated with the left handservice bay 13 and network 200 may not be associated with the right handservice bay 14. Moreover, depending on the design of the library, it maynot be necessary to have a left hand service bay 13 and/or a right handservice bay 14 at all.

An automated data storage library 10 typically comprises one or morecontrollers to direct the operation of the automated data storagelibrary. Moreover, host computers and data storage drives typicallyinclude similar controllers. A library controller may take manydifferent forms and may comprise, for example, but is not limited to, anembedded system, a distributed control system, a personal computer, aworkstation, etc. The term “library controller” as used herein isintended in its broadest sense as a device that includes at least oneprocessor, and optionally further circuitry and/or logic, forcontrolling and/or providing at least some aspects of libraryoperations.

Referring now to FIG. 4, a typical controller 400 is shown with aprocessor 402, Random Access Memory (RAM) 403, nonvolatile memory 404,device specific circuits 401, and I/O interface 405. Alternatively, theRAM 403 and/or nonvolatile memory 404 may be contained in the processor402 as could the device specific circuits 401 and I/O interface 405. Theprocessor 402 may comprise, for example, an off-the-shelfmicroprocessor, custom processor, Field Programmable Gate Array (FPGA),Application Specific Integrated Circuit (ASIC), discrete logic, etc. TheRAM 403 is typically used to hold variable data, stack data, executableinstructions, etc.

According to various aspects, the nonvolatile memory 404 may compriseany type of nonvolatile memory such as, but not limited to, ElectricallyErasable Programmable Read Only Memory (EEPROM), flash Programmable ReadOnly Memory (PROM), battery backup RAM, hard disk drives, etc. However,the nonvolatile memory 404 is typically used to hold the executablefirmware and any nonvolatile data. Moreover, the I/O interface 405comprises a communication interface that allows the processor 402 tocommunicate with devices external to the controller. Examples maycomprise, but are not limited to, serial interfaces such as RS-232, USB(Universal Serial Bus) or Small Computer Systems Interface (SCSI). Thedevice specific circuits 401 provide additional hardware to enable thecontroller 400 to perform unique functions including, but not limitedto, motor control of a cartridge gripper. Moreover, the device specificcircuits 401 may include electronics that provide, by way of example butnot limitation, Pulse Width Modulation (PWM) control, Analog to DigitalConversion (ADC), Digital to Analog Conversion (DAC), etc. In addition,all or part of the device specific circuits 401 may reside outside thecontroller 400.

While the automated data storage library 10 is described as employing adistributed control system, the various aspects described and/orsuggested herein may be implemented in various automated data storagelibraries regardless of control configuration, including, but notlimited to, an automated data storage library having one or more librarycontrollers that are not distributed. Moreover, a library controller maycomprise one or more dedicated controllers of a library, depending onthe desired approach. For example, there may be a primary controller anda backup controller. In addition, a library controller may comprise oneor more processor nodes of a distributed control system. According toone example, communication processor node 50 (e.g., of FIG. 3) maycomprise the library controller while the other processor nodes (ifpresent) may assist the library controller and/or may provide backup orredundant functionality. In another example, communication processornode 50 and work processor node 52 may work cooperatively to form thelibrary controller while the other processor nodes (if present) mayassist the library controller and/or may provide backup or redundantfunctionality. Still further, all of the processor nodes may comprisethe library controller. According to various aspects described and/orsuggested herein, a library controller may have a single processor orcontroller, or it may include multiple processors or controllers.

FIGS. 5A-5B illustrate the front 501 and rear 502 views of a datastorage drive 15, according to one approach. In the example depicted inFIGS. 5A-5B, the data storage drive 15 comprises a hot-swap drivecanister, which is in no way intended to limit the invention. In fact,any configuration of data storage drive may be used whether or not itincludes a hot-swap canister. As discussed above, a data storage drive15 is used to read and/or write data with respect to the data storagemedia, and may additionally communicate with a memory which is separatefrom the media, and is located within the cartridge. Thus, according toone approach, a data storage cartridge may be placed into the datastorage drive 15 at opening 503.

Furthermore, FIG. 6 illustrates an approach of a data storage cartridge600 with a cartridge memory 610 shown in a cutaway portion of theFigure, which is in no way intended to limit the invention. In fact, anyconfiguration of data storage cartridge may be used whether or not itcomprises a cartridge memory. According to various aspects, media of thedata storage cartridge media may include any type of media on which datamay be stored, including but not limited to magnetic media, e.g.,magnetic tape, disks, etc.; optical media, e.g., optical tape, discs,etc.; electronic media, e.g., PROM, EEPROM, flash PROM, CompactFlash™,Smartmedia™, Memory Stick™, etc.; etc., or other suitable media.Moreover, an example of a data storage cartridge that is widely employedin automated data storage libraries for mass data storage is a magnetictape cartridge in which the media is magnetic tape.

Looking now to FIGS. 7A-7B, a multi-cartridge deep slot cell 100 havingbiasing springs 152 is depicted according to one approach. As shown inthe illustrative configuration, the multi-cartridge deep slot cell 100comprises a housing 110 defining an interior space 115. Furthermore, aplurality of storage slots 120 is disposed within the housing, and maybe configured for storing up to a plurality of data storage cartridges600, depending on the desired approach. Alternatively, themulti-cartridge deep slot cell 100 may be built into the frame of theautomated data storage library according to one approach.

FIGS. 8A-8D illustrate an approach of a cartridge blocking mechanism 150having a retaining gate 660 that retains the data storage cartridges inthe multi-cartridge deep slot cell 100 according to one approach. Asillustrated, according to one approach, the retaining gate 660 may beexternally attached to a multi-cartridge deep slot cell 100, relative toa front opening of the multi-cartridge deep slot cell 100, whereby theretaining gate 660 can be activated by an accessor 18, e.g., of anautomated tape library. Moreover, the retaining gate 660 allows forpositive cartridge retention against the pressure of biasing springs(see 152 of FIGS. 7A-7B), and ensures that one or more data storagecartridges do not get pushed out of the multi-cartridge deep slot cell100 simultaneously, while allowing the pushing mechanism (not shown) ofthe multi-cartridge deep slot cell 100 to continuously push data storagecartridge(s) to the opening in a multi-cartridge deep slot cell 100.Thus, according to one approach, the accessor 18 may open the retaininggate to gain access to the data storage cartridge in tier 1 and, uponits extraction, the biasing spring 152 moves the cartridge(s) positionedbehind the extracted cartridge forward, thereby promoting thecartridge(s) by one tier as will soon become apparent.

The basic working of the retaining gate is that the gate prevents thedata storage cartridge(s) from being pushed out of a multi-cartridgedeep slot cell 100. For example, as shown in FIGS. 8A-8D, a retaininggate 660 can be lifted by, for example, accessor 18 or by a frontstorage cartridge 642 for cartridge removal from/insertion into amulti-cartridge deep slot cell 100. Specifically, retaining gate 660 hasa pivoting arm 661 mounted on multi-cartridge deep slot cell 100 via apivoting post (not shown) that can be integral to a construction ofmulti-cartridge deep slot cell 100. Pivoting arm 661 is located below acatch 662 of retaining gate 660 whereby a thrust force TF through datastorage cartridge 644-642 caused by the pushing mechanism (not shown) ofmulti-cartridge deep slot cell 100 causes retaining gate 660 to stayclosed in a retaining position as shown in FIG. 8A. Moreover, theretaining gate 660 is preferably biased such that it closes in thedownward direction over the front opening of multi-cartridge deep slotcell 100. This constant biasing may be achieved via gravity as shown inFIG. 8A or by implementing a spring force, e.g., attached to retaininggate 660 (not shown).

For removal of front storage cartridge 642 by accessor 18 frommulti-cartridge deep slot cell 100, retaining gate 660 must be liftedupward to a releasing position whereby catch 662 of retaining gate 660is disengaged from front storage cartridge 642. This can be seen in FIG.8B where accessor 18 interfaces with retaining gate 660 by providing alifting force. Once retaining gate 660 is lifted to the releasingposition and accessor 18 is engaged with storage cartridge 642, accessor18 can pull storage cartridge 642 out of multi-cartridge deep slot cell100 and into accessor 18 without any interference of retaining gate 660as shown in FIG. 8C. In view of storage cartridges 644 and 643 beingstored in multi-cartridge deep slot cell 100, retaining gate 660 mustreturn to its retaining position to prevent storage cartridges 644 and643 from being ejected from multi-cartridge deep slot cell 100 by thethrust force TF of the pushing mechanism (not shown). During extractionof front storage cartridge 642 through the front opening ofmulti-cartridge deep slot cell 100, the retaining gate 660, which isbeing biased downward, moves back to the retaining position to engagestorage cartridge 643.

Once front storage cartridge 642 is extracted and storage cartridges 643and 644 are retained from being pushed out of multi-cartridge deep slotcell 100, retaining gate 660 has successfully completed its cartridgeretrieval process. Now retaining gate 660 demonstrates its ability towork for cartridge insertion into multi-cartridge deep slot cell 100.When accessor 18 begins to insert storage cartridge 642 back intomulti-cartridge deep slot cell 100, retaining gate 660 is lifted to itsreleasing position to allow storage cartridge 642 through the frontopening of multi-cartridge deep slot cell 100. Catch 662 of retaininggate 660 interfaces with a rear portion of storage cartridge 642, inparticular a beveled surface of catch 662 as shown in FIG. 8D, wherebyretaining gate 660 is lifted to its releasing position as shown in FIG.8B due to storage cartridge 642 being pushed in multi-cartridge deepslot cell 100 by accessor 18. In doing so, storage cartridges 644, 643are pushed deeper into multi-cartridge deep slot cell 100 by storagecartridge 642 in multi-cartridge deep slot cell 100 by accessor 18.Thus, the accessor is able to provide a force greater than the thrustforce TF antiparallel thereto, to overcome the directional biasing ofthe storage cartridges 644, 643. Upon full insertion intomulti-cartridge deep slot cell 100, retaining gate 660 moves to itsretaining position to engage storage cartridge 642 as shown in FIG. 8A.

Thus, looking to various aspects presented herein, access to a storageslot may include the ability to remove a cartridge from a storage slot,the ability to place a cartridge into a storage slot, or combinationsthereof.

According to an exemplary approach, the storage slots from top to bottomare considered to be in parallel and comprise the same tier. Moreover,the storage slots from front to back, in a particular row, areconsidered to be in series and comprise sequential tiers.

Referring back to FIGS. 7A-7B, in accordance with one approach, storageslots 120 are depicted as being configured for storing up to a pluralityof data storage cartridges 600, and arranged in sequential order oftiers 621, 622, 623, 624, 625 from front to rear. It should be notedthat the frontmost tier 621 is also called “tier 1”, while the next tier622 is called “tier 2”, etc., and the last tier 625 is also called the“rearmost” tier. However, referring to FIG. 2, in one approach, thesingle cartridge storage slots 16 are also termed “tier 0”.

Referring again to FIGS. 1-3, according to one approach, the controllerof automated data storage library 10 may operate the accessor(s) 18, 28to selectively extract, place and/or transport data storage cartridgeswith respect to the multi-cartridge deep slot cells 100 and/or otherelements of the automated data storage library 10. For example, thecontroller may facilitate extracting a cartridge from a multi-cartridgedeep slot cell 100, transporting the cartridge to a data storage drive15 and placing the cartridge in the drive 15. The controller may thenextract the cartridge from the data storage drive 15, while directingthe accessor to transport the cartridge to a specific multi-cartridgedeep slot cell 100, and place the cartridge therein.

In one configuration, one or more data storage cartridges may be addedinto the library, e.g., at an I/O station 24, 25, whereby the controllerof the automated data storage library 10 may then operate theaccessor(s) 18, 28 to transport the cartridge(s) to specificmulti-cartridge deep slot cell(s) 100, and place the cartridge(s)therein. Similarly, the controller may operate the accessor(s) toselectively extract, place and transport data storage cartridges withrespect to the single cartridge storage slots 16, and/or transportinserted or added cartridge(s) to specific single cartridge storageslots 16.

Now referring to FIG. 9, a storage system 900 is shown according to oneapproach. Note that some of the elements shown in FIG. 9 may beimplemented as hardware and/or software, according to various aspects.In some approaches, the storage system 900 may be implemented in anautomated data storage library such as that shown in FIGS. 1-2. In otherapproaches, an automated data storage library such as that shown inFIGS. 1-2 may be a tier of the storage system 900.

The storage system 900 may include a storage system manager 912 forcommunicating with a plurality of media on at least one higher storagetier 902 and at least one lower storage tier 906. The higher storagetier(s) 902 preferably may include one or more random access and/ordirect access media 904, such as hard disks in hard disk drives (HDDs),nonvolatile memory (NVM), solid state memory in solid state drives(SSDs), flash memory, SSD arrays, flash memory arrays, etc., and/orothers noted herein or known in the art. The lower storage tier(s) 906may preferably include one or more lower performing storage media 908,including sequential access media such as magnetic tape in tape drivesand/or optical media, slower accessing HDDs, slower accessing SSDs,etc., and/or others noted herein or known in the art. One or moreadditional storage tiers 916 may include any combination of storagememory media as desired by a designer of the system 900. Also, any ofthe higher storage tiers 902 and/or the lower storage tiers 906 mayinclude some combination of storage devices and/or storage media.

The storage system manager 912 may communicate with the storage media904, 908 on the higher storage tier(s) 902 and lower storage tier(s) 906through a network 910, such as a storage area network (SAN), as shown inFIG. 9, or some other suitable network type. The storage system manager912 may also communicate with one or more host systems (not shown)through a host interface 914, which may or may not be a part of thestorage system manager 912. The storage system manager 912 and/or anyother component of the storage system 900 may be implemented in hardwareand/or software, and may make use of a processor (not shown) forexecuting commands of a type known in the art, such as a centralprocessing unit (CPU), a field programmable gate array (FPGA), anapplication specific integrated circuit (ASIC), etc. Of course, anyarrangement of a storage system may be used, as will be apparent tothose of skill in the art upon reading the present description.

In more approaches, the storage system 900 may include any number ofdata storage tiers, and may include the same or different storage memorymedia within each storage tier. For example, each data storage tier mayinclude the same type of storage memory media, such as HDDs, SSDs,sequential access media (tape in tape drives, optical disc in opticaldisc drives, etc.), direct access media (CD-ROM, DVD-ROM, etc.), or anycombination of media storage types. In one such configuration, a higherstorage tier 902, may include a majority of SSD storage media forstoring data in a higher performing storage environment, and remainingstorage tiers, including lower storage tier 906 and additional storagetiers 916 may include any combination of SSDs, HDDs, tape drives, etc.,for storing data in a lower performing storage environment. In this way,more frequently accessed data, data having a higher priority, dataneeding to be accessed more quickly, etc., may be stored to the higherstorage tier 902, while data not having one of these attributes may bestored to the additional storage tiers 916, including lower storage tier906. Of course, one of skill in the art, upon reading the presentdescriptions, may devise many other combinations of storage media typesto implement into different storage schemes, according to the approachespresented herein.

According to some approaches, the storage system (such as 900) mayinclude logic configured to receive a request to open a data set, logicconfigured to determine if the requested data set is stored to a lowerstorage tier 906 of a tiered data storage system 900 in multipleassociated portions, logic configured to move each associated portion ofthe requested data set to a higher storage tier 902 of the tiered datastorage system 900, and logic configured to assemble the requested dataset on the higher storage tier 902 of the tiered data storage system 900from the associated portions. Of course, this logic may be implementedas a method on any device and/or system or as a computer programproduct, according to various aspects.

Cooling data centers is a very important and complex balance ofcost/energy efficiency and preserving the integrity/reliability of datastorage equipment. Problems occur when a library door is opened foroperator and/or service access. When a library door is opened, unsafe,outside air may enter the enclosure. Data storage media and/or datastorage equipment may be damaged if the ambient temperature and/or therelative humidity of the air entering the enclosure is outside the safeand/or functional operating limits of the data storage media and/or datastorage equipment.

In order to place some of the inventive concepts disclosed herein incontext, much of the description refers to tape equipment and tapedrives. This has been done by way of example only, and the conceptsdisclosed in the various exemplary approaches may be readily applied toany type of data storage media, associated equipment and/or storagethereof. Furthermore, a tape drive may include any type of tape driveknown in the art. The inventive concepts disclosed herein may beadaptable to future tape-related products without straying from thescope and spirit of the present invention.

In a self-cooling library, when the ambient temperature and/or relativehumidity of the data center becomes warm and moist (e.g. at atemperature of 35 degrees Celsius and 80% relative humidity), the tapedrives inside the library may have an internal temperature ofapproximately 25 degrees Celsius. This internal temperature is below thedew point temperature of the outside air. If the internal temperature isbelow the dew point temperature of the outside air, in response toopening the front door of the library, the outside air may enter thetape drive and water vapor may condense on the tape drive read/writehead element and/or other sensitive elements. Condensation may result inpermanent damage, e.g., corrosion, to the tape drive read/write headelement and/or other sensitive elements.

The tape drives in a self-cooling library are housed in tape drivecanister assemblies that include cooling fans that draw air from thefront of the tape drive canister and exhaust air out of the back of thetape drive canister. The front of the tape drive canister typicallyfaces the door of the library enclosure so that the tape drive canistercooling fans actively pull the warm and moist air through the tapedrive. This active pulling of warm and moist air through the tape driveincreases the probability that condensation occurs in the tape drive.

Another problem that may arise in a self-cooling library involvesinadequate internal air mixing. Inadequate internal air mixing maycreate warm and cold regions in the library. The warm and cold regionsin the library may result in tape drives maintained at varying operatingtemperatures. Different operating temperatures in the library may resultin undesirable variations in the long-term reliability of the tapedrives and may reduce the probability that all tapes may be read on alldrives.

A prior attempt to address condensation and air mixing issues includesimplementing an indicator on the front of the library that lights whenthe tape drive internal temperature and relative humidity are such thatcondensation is possible. The indicator light warns that the door shouldnot be opened at that time.

A drawback to this attempted approach is that the inside of the librarycannot be accessed when the indicator light is on and, therefore, anyoperator and/or service action is delayed until the environmentalconditions in the library change sufficiently to turn off the indicatorlight. This delay may be hours or days.

Further attempts to address condensation and/or air mixing issuesinclude putting tape drive canisters into a “self-protect mode.” In aself-protect mode, the cooling fans in the tape drive canister areturned off to prevent condensation by keeping warm and moist air fromentering the tape drives. The tape drive internal temperature rises whencooling fans in the tape drive canister are turned off. The increase inthe tape drive internal temperature decreases the probability that thesensitive head component is below the dew point temperature so thatcondensation is less likely not occur. However, the tape drive internalelectronics eventually reach the maximum operating temperature when thetape drive canister's cooling fans are turned off. In response toreaching the tape drive internal electronics' maximum operatingtemperature, the tape drive canister's cooling fans turn on for asufficient time to cool down the internal electronics. The tape drivecanister's cooling fans draw the moist, ambient air into the tape drive,but the head component is warmed to above the dew point temperature. Inresponse to the tape drive internal electronics cooling off, the tapedrive canister's cooling fans turn off. The tape drive canisters in aself-protect mode continue this on-off cycling as long as the tape drivecanisters are in self-protect mode.

A drawback to this attempted approach is that the self-protect mode maynot sufficiently prevent condensation on the head element if the tapedrive canister cooling fans are turned on before the internaltemperatures have risen to above the dew point of the outside air.

Moreover, the swings in temperature are more likely to cause thermaldegradation of the sensitive drive components. Additionally, repeatedlyraising and lowering the temperatures in the self-protect mode maycreate stress on the components and/or solder joints of the tape driveinternal electronics. Stress on the components and/or solder joints ofthe tape drive internal electronics may lower the long-term reliabilityof the tape drive.

Some of the inventive concepts herein illustrate an air curtaingenerator comprising fans which draw air from the back of the libraryframe. The fans exhaust the air along the front of the tape drivecanister slots through a nozzle which has a downward-directed narrowopening. The downward-directed narrow opening may create a relativelyhigh volume and high velocity exhaust airflow. The airflow through thedownward-directed narrow opening may create a wide but thin “curtain” ofair in a predefined trajectory between the accessor aisle and the tapedrive canister slots.

The volume and velocity of the airflow is preferably sufficient tocreate an air curtain that prevents unwanted mixing of the relativelycooler, circulating air and potentially warmer, ambient air from theaccessor aisle. The warm, ambient air is referred to hereininterchangeably as “outside air.” Air from the accessor aisle may alsobe referred to herein interchangeably as “outside air.” As noted above,the ambient air may increase in temperature and/or humidity when thedoor of the library is opened thereby allowing air from outside thelibrary to enter the accessor aisle.

The air curtain generator with the nozzle creates an air curtain havinga velocity that is sufficient to create a barrier to outside air and/orminimize unwanted mixing of the outside air with air passing backthrough the tape drive canisters. The airflow through the nozzle createsa “barrier” such that the intermixing is less than 10% intermixing ofoutside air with the air in the air curtain that is drawn back into thetape drive canisters. The intermixing may be less than approximately10%, 9%, 8%, 7%, 6%, 5%, 4%, 3%, 2%, or 1% intermixing of outside airwith the air in the air curtain that is drawn back into the tape drivecanisters. In another approach, the intermixing may be 0%.

A “full air curtain” may comprise an air curtain which protects alloccupied drive slots in a storage library. The full air curtain maycross the entire front of the occupied slots in a storage library. Thevolume of air per unit time entering a full air curtain across theentire front of the occupied drive slots may be at least as great as avolume of air that the fans in the drives cumulatively draw per the sameunit of time, and preferably greater.

The air curtain may be thin enough to be effective even if an accessor(as described above in reference to FIG. 2) is located in front of thedrives being protected by the air curtain. Moreover, the protrusion ofthe downward-directed narrow opening of the nozzle may be limited by theeffective operation path of the accessor and/or other components in thelibrary as described above in regard to FIG. 2 and other Figures.

In an exemplary approach, the air curtain generator is an air curtaincanister comprising a fan and a nozzle for directing the airflow exitingthe housing in a predefined trajectory for creating an air curtain. Theair curtain canister may comprise a housing having a form factorapproximating an exterior of a data storage drive. The air curtaincanister may be insertable into a drive slot of a data storage library.

An example of an insertable air curtain canister may comprise a housinghaving a form factor approximating an exterior of a tape drive canisterwhich is insertable into a tape library. The air curtain canister may beinstalled above other tape drive canisters in the same column and frame.When the air curtain canister fans are running, the air curtain flowsvertically down in front of the tape drive canisters below.

In one configuration, the nozzle may direct the air curtain verticallydown and fan out to the sides in order to cover drive slots that are notdirectly below the air curtain canister. The nozzle may includeadditional fans and/or baffles which direct the air in a widerconfiguration than an airflow directed vertically straight downwards. Inone approach, the air curtain canister may be located in the center ofan array of tape drive canisters and is configured to direct the aircurtain airflow in front of tape drive canisters directly below orindirectly below the air curtain canister. In other approaches, the aircurtain canister is not limited to a location above the tape drivecanister(s) to be protected. For example, the air curtain canister maybe located below the tape drive canister(s) to be protected and directthe air curtain vertically upwards. In another example, the air curtaincanister may be located to the left and/or the right of the tape drivecanister(s) to be protected and direct the air curtain horizontallyacross the tape drive canister(s) to be protected.

In another approach, the nozzle protruding from the air curtain canisteris wider than a single tape drive slot and directs air in the aircurtain vertically down in front of tape drive slots which are directlybelow the air curtain canister and tape drive slots which are indirectlybelow the air curtain canister. A nozzle of the air curtain canisterwhich is wider than one tape drive canister may protect a horizontalarray of tape drive canisters.

The air curtain canister may be positioned above one or more tape drivecanisters to be protected. The air curtain canister may additionally bepositioned above an array of tape drive canisters. There may be one ormore air curtain canisters protecting one or more tape drive canisters.

The cooling air drawn into the tape drive canisters originates from theair curtain airflow rather than the air in the accessor aisle at thefront of the library. The cooling air drawn into the tape drivecanisters originates from the air curtain airflow rather than the airfrom outside the library even if the door is an open configuration.

In a preferred approach, the air curtain generator is not limited to anair curtain canister. The air curtain generator may be a separateventing component above the tape drive canister(s) to be protected suchthat air curtain generation does not limit or reduce the capacity of thestorage frame. In other approaches, the air curtain generator is notlimited to a location above the tape drive canister(s) to be protected.For example, the air curtain generator may be located below the tapedrive canister(s) to be protected and direct the air curtain verticallyupwards. In another example, the air curtain generator may be located tothe left and/or the right of the tape drive canister(s) to be protectedand direct the air curtain horizontally across the tape drivecanister(s) to be protected.

Various inventive approaches as described herein may be implemented anytype of tape library, such as in the IBM TS4500 Tape Library and anyassociated canister packages. (International Business Machines (IBM), 1New Orchard Road, Armonk, N.Y. 10504-1722, United States). Of course,the inventive aspects may be implemented in any data storage library aswould be understood by one having ordinary skill in the art.

FIG. 10 illustrates a data storage library 1000 which stores andretrieves data storage cartridges, containing data storage media, frommulti-cartridge deep slot cells and single cartridge storage slots. Asan option, the present data storage library 1000 may be implemented inconjunction with features from any other approach listed herein, such asthose described with reference to the other FIGS. For example, FIGS.15-20 depict various configurations of the automated tape library ofFIG. 10. Of course, however, such a data storage library 1000 and otherspresented herein may be used in various applications and/or inpermutations which may or may not be specifically described in theillustrative configurations listed herein. Further, the data storagelibrary 1000 presented herein may be used in any desired environment.Moreover, it should be noted that references to “data storage media”herein refer to data storage cartridges, and for purposes of the presentapplication, the two terms may be used synonymously.

The data storage library 1000 of FIG. 10 comprises one or more storageframes 1001. One or more of the storage frames 1001 may be coupled toone or more air conditioning units 1002. A frame may comprise anexpansion component of the library. Thus, storage frames may be added orremoved to expand or reduce the size and/or functionality of thelibrary. According to different approaches, frames may includeadditional storage slots, deep slot cells, drives, import/exportstations, accessors, operator panels, etc.

The air conditioning units 1002 may be a CRAC unit, a central airconditioning unit, a ductless mini-split air conditioning unit, a hybridair conditioner, a heating, ventilation, and air conditioning (HVAC)system, etc. The air conditioning units 1002 may be of any type known inthe art.

An example of an automated data storage library which has a similarconfiguration as that depicted in FIG. 10 and may be implemented withsome of the various aspects herein is the IBM TS4500 Tape Library.

FIGS. 11A-11B illustrate the front perspective view and rear perspectiveview of a tape drive canister 1100, according to one approach.

As an option, the present tape drive canister 1100 may be implemented inconjunction with features from any other approach listed herein, such asthose described with reference to the other FIGS. Of course, however,such tape drive canister 1100 and others presented herein may be used invarious applications and/or in permutations which may or may not bespecifically described in the illustrative configurations listed herein.Further, the tape drive canister 1100 presented herein may be used inany desired environment.

As discussed above, a tape drive canister is used to read and/or writedata with respect to the data storage media and may additionallycommunicate with a memory which is separate from the media and islocated in the cartridge. According to one approach, a cartridge may beplaced into the opening 1102 of the tape drive canister 1100. See alsoopening 503 of data storage drive 15 at (FIG. 5A).

FIGS. 12A-12B illustrate the front perspective view and rear perspectiveview of an air curtain canister 1200, respectively, according to oneapproach. As an option, the present air curtain canister 1200 may beimplemented in conjunction with features from any other approach listedherein, such as those described with reference to the other FIGS. Ofcourse, however, such air curtain canister 1200 and others presentedherein may be used in various applications and/or in permutations whichmay or may not be specifically described in the illustrativeconfigurations listed herein. Further the air curtain canister 1200presented herein may be used in any desired environment.

As shown in FIG. 12A-12B, the air curtain canister 1200 comprises ahousing 1204, guide features 1206, an electronic docking feature 1207, anozzle 1208, and a rear cover 1210 with air inlets to allow air to enterthe canister from the back of a frame of a data storage library.

In an exemplary approach, the air curtain canister comprises a housing1204 having a form factor approximating an exterior of a data storagedrive. The housing 1204 having a form factor approximating an exteriorof a data storage drive may be insertable into a drive slot of a datastorage library. An example of such a data storage drive and datastorage library includes a tape drive, e.g., the tape drive canister1100 of FIG. 11A and a tape storage library. The tape drive may be anyknown tape drive usable with any tape storage library. The inventiveconcepts disclosed herein may be adaptable to future tape-relatedproducts without straying from the scope and spirit of the presentinvention.

The air curtain canister may comprise a nozzle 1208 for directing theairflow exiting the housing 1204 in a predefined trajectory for creatingan air curtain. In one approach, the nozzle 1208 is located at the frontof the air curtain canister and comprises a downward-directed narrowopening. The downward-directed narrow opening may allow a relativelyhigh volume and velocity airflow to exhaust from the air curtaincanister such that the airflow creates a wide but thin “curtain” of air.

In one configuration, the nozzle 1208 may be controllable such that thedirection of the airflow may be modified. For example, the angle and/orshape of the downward-directed narrow opening may be adjustable tocreate a wider and/or narrower air curtain. The nozzle may comprise oneor more individually controllable baffles for directing the air curtain.In one approach, the nozzle comprises venting air diverters foradjusting the angle of the airflow in order to change the direction ofthe air curtain and/or to create a wider and/or narrower air curtain.

In another approach, the air curtain canister includes one or more fans(described further in detail below in FIG. 13) internally, within theair curtain canister for creating an airflow in the housing 1204, e.g.,in a continuous mode, in response to detecting a trigger condition, etc.

In one approach, the fans may be individually controllable such that oneor more of the fans may be turned off and on, the speed of the fans maybe adjusted, a second fan may start only when a trigger condition occursas a boosting effect, one or more of the fans are capable of reversingdirections, etc.

In one configuration, the air curtain canister comprises a cold airinlet (not shown) for receiving relatively cooler air for mixing withair in the airflow. The air curtain canister may comprise one or morecold air inlets. The cold air inlets may receive relatively cooler airfor mixing with air in the airflow from one or more sources ofrelatively cooler air. Cold air may be used interchangeably herein torefer to “relatively cooler air.”

In one configuration, the cold air inlet receives relatively cooler airfor mixing with air in the airflow from one or more air conditioningunits which are positioned above the air curtain canisters. The airconditioning unit may be of any type known in the art. The airconditioning unit may be a CRAC unit, a central air conditioning unit, aductless mini-split air conditioning unit, a hybrid air conditioner, aHVAC system, etc.

In another approach, the air curtain canister may include a valve forselectively controlling an amount of relatively cooler air mixed withthe air in the airflow created by the fan. The valve may be a globevalve, a gate valve, a ball valve, a butterfly valve, a plug valve, acheck valve, a diaphragm valve, a needle valve, a pinch valve, or anyother valve known in the art. In one approach, the air curtain canistermay comprise any combination of valves and/or fans for selectivelycontrolling an amount of relatively cooler air mixed with the air in theairflow.

In yet another approach, the air curtain canister comprises an internalmixing chamber (described further in detail below in FIG. 13) for mixingthe relatively cooler air with the air in the airflow prior toexhausting the mixed air as the air curtain. The mixing chamber maycomprise temperature and/or humidity sensors for determining whether theair is at the proper temperature and/or humidity level to be exhaustedas the air curtain. If the air is not, then adjustments can be made suchas manipulating the aforementioned valve, fan speed, etc.

In another approach, the air curtain canister does not comprise aninternal mixing chamber. The mixing of the relatively cooler air withair in the airflow may occur as the air is moved by the fans.

In an exemplary approach, the guide features 1206 comprise appropriateexternal mechanical features so as to fit a single air curtain canisterinto a single drive slot of the tape library storage frames. The guidefeatures 1206 may comprise appropriate dimensions so as to fit a singleair curtain canister into a single drive slot of the tape librarystorage frames. The guide features may include a slide and lock system,a slide-rail assembly, magnetic catches, friction catches, ball bearingslides, or any other locking and/or mounting mechanisms known in theart.

An air curtain canister may comprise appropriate external electricalfeatures so as to fit a single air curtain canister into a single driveslot of the tape library storage frames. In one approach, the aircurtain canister may comprise an electronic docking feature 1207 whichmay be electronically configured to receive commands, alerts, sensorreadings, etc. as a tape drive canister inserted into a drive slot maybe capable of, as known in the art. The electronic docking feature 1207may be electronically configured to receive commands, alerts, sensorreadings, etc. regarding the operation of the air curtain canister suchas commands and/or alerts to selectively control the fans and/or valves,adjust the angle of the nozzle (e.g. the angle of the airflow in the aircurtain), etc. According to one approach, an air curtain canister may beplaced in the data storage drive at opening 15 (FIG. 2).

In a further approach, the air curtain canister may comprise one or moreof any sensors known in the art. In one approach, the one or moresensors may be temperature sensors, humidity sensors, mass airflowsensors, pressure sensors, etc. to monitor the state of the air as wouldbe understood by one having ordinary skill in the art.

A temperature sensor may be a negative temperature coefficient (NTC)thermistor, a resistance temperature detector (RTD), a thermocouple, asemiconductor-based sensor, an infrared sensor, a bimetallic device, athermometer, a change-of-state sensor, etc. The temperature sensor maybe any temperature sensor known in the art.

A humidity sensor may be a capacitive sensor, a resistive sensor, athermally conductive sensor, etc. The humidity sensor may be anyhumidity sensor known in the art.

In one configuration, the air curtain canister may comprise a heater forheating air in the airflow. The heater may comprise one or more nichromewire coils, ionic heating elements, tourmaline heating elements, ceramicheating elements, porcelain heating elements, infrared heating elements,titanium heating elements, or any other heating elements known in theart. The heater(s) may be used to heat air in the airflow in order toheat sensitive components of the tape drive canister to above the dewpoint of the outside air to prevent condensation.

In one approach, the velocity of the air in the airflow created by thefan in the air curtain canister is sufficient to create a barrier tooutside air. The fan and nozzle for directing the airflow create avelocity of airflow in the air curtain such that the intermixing is lessthan 10% intermixing of outside air with the air drawn into the tapedrives behind the air curtain. The intermixing may be less thanapproximately 10%, 9%, 8%, 7%, 6%, 5%, 4%, 3%, 2%, or 1% intermixing ofoutside air with the air drawn into the tape drives. In anotherapproach, the intermixing may be 0%.

The rear perspective view of the air curtain canister 1200 comprises arear cover 1210 with air inlets to allow air to enter the canister fromthe back of the frame. The air inlets to allow air to enter the canisterfrom the back of the frame may be the same and/or, in addition to, thecold air inlets as discussed above. In one approach, the air inlets maycomprise one or more cold air inlets for mixing relatively cooler airwith air in the airflow.

In one configuration, an air curtain canister configured primarily forcontinuous mode operation may have a different air inlet physical designthan an air curtain canister configured primarily for recirculation modeoperation. The continuous mode air curtain canister may include similarhousing dimensions and features. The continuous mode air curtaincanister may additionally include inlets to draw air from multiplesources of temperature and/or humidity controlled air.

In one approach of a continuous mode air curtain canister as describedabove, the additional cold air inlets may be directed upward. Additionalcold air inlets may be located near the opening where relatively coolerair from the integrated cooling air conditioner directs relativelycooler air into the accessor aisle. The cold air inlet allows relativelycooler air to enter the air curtain canister and flow through aninternal chamber (e.g. the mixing chamber). The relatively cooler airmay then be mixed with the warmer, recycled air being drawn into therear of the air curtain canister by the fan. The mixed intermediatetemperature air may then be pushed by the fan into the air curtainvertically downward toward the tape drive canisters below the aircurtain canister.

Furthermore, FIG. 13 illustrates a perspective view of the air curtaincanister 1200 of FIGS. 12A-12B with a cover removed. As shown, the aircurtain canister 1200 comprises a fan 1302 and a mixing chamber 1304.

In one approach, the fan 1302 may comprise one or more fans. The fan1302 may comprise one or more blade fans, centrifugal blowers, positivedisplacement blowers, squirrel cage blowers, other blowers, or any othertype of apparatus for creating a current of air known in the art.

In one configuration, at least two fans are mounted side by side toincrease the volume of airflow. Fans which are mounted side by side maydraw air from the rear of the canister and push the air toward the frontof the housing. In a preferred approach, the fan 1302 may be two, 60mm×60 mm square fans.

In one approach, the fans may be individually controllable such that oneor more of the fans may be turned off and on, the speed of the fans maybe adjusted, a second fan may start only when a trigger condition occursas a boosting effect, one or more of the fans are capable of reversingdirections, etc.

In one configuration, one or more fans may be individually controllablesuch that one or more fans may be turned off until the fan(s) areinstructed to turn on. In another approach, the one or more fans may beindividually controllable such that one or more of the fans may beturned on until one or more of the fans are instructed to turn off.

In yet another approach, a second fan may be turned off and, in responseto a trigger condition, turned on to create a boosting effect. Aboosting effect may increase the mixing of relatively cooler air withair in the airflow. A boosting effect may include turning on a secondfan to increase the velocity of the airflow in the air curtain and/orthroughout the housing.

In another approach, reversing the direction of the one or more fans mayreverse the direction of the airflow. The fans may reverse the directionof the airflow in order to adjust the intermixing between the outsideair and the air in the air curtain that is drawn into the tape drivecanisters. The direction of the fan may be reversed in response to atrigger condition.

As mentioned several times above, various actions such as starting oneor more fans, adjusting a valve, etc. may occur upon detecting a triggercondition. A trigger condition may include detecting opening of a frontdoor of the data storage library, receiving a command to run the fanfrom a user, occurrence of a specific time based on a predeterminedschedule, sensing the temperature is too high based on a predefinedoperating temperature threshold, sensing the temperature is too lowbased on a predefined operating temperature threshold, sensing thehumidity is too high based on a predefined operating humidity threshold,and sensing the humidity is too low based on a predefined operatinghumidity thresholds, etc. The predefined operating temperature thresholdmay be a temperature of the outside air at or above which condensationcould occur if the outside air is drawn into the tape drives. Thepredefined operating temperature threshold may be above optimaltemperatures for tape drive operation. The predefined operating humiditythreshold may be a humidity level of the outside air at or above whichcondensation could occur if the outside air is drawn into the tapedrives. The predefined operating humidity threshold may be above optimalhumidity levels for tape drive operation.

In one configuration, the air curtain canister may comprise a mixingchamber 1304 for mixing the relatively cooler air with the air in theairflow. The mixing chamber may comprise temperature and/or humiditysensors for determining whether the mixture of the relatively cooler airand the air in the airflow has the desired characteristics for the aircurtain. Determining whether the mixed air has the desiredcharacteristics for the air curtain may include a determination that airin the mixing chamber has reached a predetermined temperature, a rangeof predetermined temperatures, a predetermined humidity level, a rangeof predetermined humidity levels, etc. In a preferred approach, thedetermination is based on a combination of the foregoing factors.

In another approach, the interior of the air curtain canister maycomprise a heater for heating air moved by the fan 1302 in the airflow.The heater may comprise one or more nichrome wire coils, ionic heatingelements, tourmaline heating elements, ceramic heating elements,porcelain heating elements, infrared heating elements, titanium heatingelements, or any other heating elements known in the art. The heater(s)may be used to heat air in the airflow in order to heat sensitivecomponents of the tape drive canister above the dew point of the outsideair to prevent condensation. The heater(s) may be positioned in themixing chamber, near the air inlet, and/or near or in the nozzle.

FIGS. 14A-14B illustrate an exemplary airflow through the air curtaincanister 1200.

In one approach, the airflow is directed by the fan 1302. The fan 1302draws air from the rear of the air curtain canister. The fan 1302 pushesthe air through the mixing chamber 1304 of the air curtain canisterwhere the air may be selectively mixed with relatively cooler air asdiscussed above. Note that the mixing chamber may also and/oralternatively be located upstream of the fan 1302, rather thandownstream as shown. The mixed air is exhausted through the nozzle 1208into the airflow which comprises the air curtain at the front of the aircurtain canister.

FIG. 15 is a partial cross-sectional side view of a storage frame 1500of the data storage library 1000 of FIG. 10 according to one approach.As an option, the storage frame 1500 may be implemented in conjunctionwith features from any other approach listed herein, such as thosedescribed with reference to the other FIGS. Of course, however, such astorage frame 1500 and others presented herein may be used in variousapplications and/or in permutations which may or may not be specificallydescribed in the illustrative configurations listed herein. Further, thestorage frame 1500 presented herein may be used in any desiredenvironment.

FIG. 15 illustrates a configuration of a storage frame in a data storagelibrary which may comprise an array of drive slots each configured toreceive a data storage drive therein, and a plurality of air curtaincanisters 1200 positioned laterally in the array of drive slots forcreating an air curtain across a front of the remaining drive slots inthe array. Each air curtain canister may comprise a housing having aform factor approximating an exterior of a data storage drive, a fan forcreating an airflow in the housing, and a nozzle for directing theairflow exiting the housing in a predefined trajectory for creating theair curtain. Exemplary air curtain canisters are described in referenceto FIGS. 12A-14B above.

In addition to one or more air curtain canisters, the data storagelibrary may comprise one or more fans which draw air from the rear ofthe array of drive slots, e.g., as generally described in reference toFIGS. 18-20, below. In one approach, the fan may comprise one or moreblade fans, centrifugal blowers, positive displacement blowers, squirrelcage blowers, other blowers, or any other type of apparatus for creatinga current of air known in the art.

In one approach, the fans may be individually controllable such that oneor more of the fans may be turned off and on, the speed may be adjusted,a second fan may start only when a trigger condition occurs as aboosting effect, one or more of the fans are capable of reversingdirections, etc.

The data storage library may include at least some of the air curtaincanisters which comprise a cold air inlet for mixing relatively coolerair with air in the airflow which is drawn into the air curtain canisterfrom the rear of the array of drive slots. The cold air inlets mayreceive relatively cooler air for mixing with air in the airflow fromone or more sources of relatively cooler air.

In one configuration, the cold air inlet receives relatively cooler airfor mixing with air in the airflow from one or more air conditioningunits which are positioned above the air curtain canisters. The airconditioning unit may be of any type known in the art. The airconditioning unit may be a CRAC unit, a central air conditioning unit, aductless mini-split air conditioning unit, a hybrid air conditioner, aHVAC system, etc.

The data storage library may comprise a robotic accessor configured tomove data storage cartridges between storage slots and drives in thedrive slots. In this approach, the air curtain position is between atravel path of the robotic accessor and the front of the array of thedrive slots. The robotic accessor may be of the type as described abovein FIGS. 1-8. In one approach, the air curtain is thin enough to beeffective even if an accessor is located in front of the drives beingprotected by the air curtain.

In one configuration, the data storage library may comprise data storagedrives in at least some of the drive slots. The air curtain canistersare positioned to create a full air curtain across the entire front ofthe occupied drive slots. The volume of air entering the full aircurtain is at least as great as the volume of air the drives in thedrive slots cumulatively draw. The volume of air entering the full aircurtain may be measured per unit time and the volume of air the drivesin the drive slots cumulatively draw may be measured per the same unitof time.

FIG. 16 illustrates a partial cross-sectional side view of a storageframe 1500 of the data storage library 1000 of FIG. 10 according to oneapproach. As an option, the storage frame 1500 may be implemented inconjunction with features from any other approach listed herein, such asthose described with reference to the other FIGS. Of course, however,such a storage frame 1500 and others presented herein may be used invarious applications and/or in permutations which may or may not bespecifically described in the illustrative configurations listed herein.Further, the storage frame 1500 presented herein may be used in anydesired environment.

FIG. 16 illustrates a configuration of a data storage library which maycomprise an array of drive slots each configured to receive a datastorage drive therein, and a plurality of air curtain canisters 1200positioned laterally in the array of drive slots for creating an aircurtain across a front of the remaining drive slots in the array. Eachair curtain canister may comprise a housing having a form factorapproximating an exterior of a data storage drive, a fan for creating anairflow in the housing, and a nozzle for directing the airflow exitingthe housing in a predefined trajectory for creating the air curtain.Exemplary air curtain canisters are described in reference to FIGS.12A-14B above.

FIG. 16 illustrates an exemplary airflow in a data storage librarycreated by an air curtain canister 1200. Paneling, ducting, and/or anyother known type of barrier may be present at the rear of the drives todirect the circulating air back to the air curtain canister 1200. In theexample shown, a panel 1502 isolates the air exiting the drives from theremaining areas of the storage frame and directs it to the air curtaincanister 1200.

The air curtain canister may operate in a recirculation mode and/or acontinuous mode, according to various approaches. In a continuous mode,the air curtain canister fans operate continuously until the air curtaincanister is instructed otherwise.

In a recirculation mode, the air curtain canister fans are turned on inresponse to a trigger condition. A trigger condition may includedetecting opening of a front door of the data storage library, receivinga command to run the air curtain canisters from a user, occurrence of aspecific time based on a predetermined schedule, sensing the temperatureis too high based on a predefined operating temperature threshold,sensing the temperature is too low based on a predefined operatingtemperature threshold, sensing the humidity is too high based on apredefined operating humidity threshold, and sensing the humidity is toolow based on a predefined operating humidity thresholds, etc. Thepredefined operating temperature threshold may be a temperature of theoutside air at or above which condensation could occur if the outsideair is drawn into the tape drives. The predefined operating temperaturethreshold may be above optimal temperatures for tape drive operation.The predefined operating humidity threshold may be a humidity level ofthe outside air at or above which condensation could occur if theoutside air is drawn into the tape drives. The predefined operatinghumidity threshold may be above optimal humidity levels for tape driveoperation.

In the recirculation mode, the tape drive canisters do not draw air fromthe accessor aisle and/or air from outside the library coming through anopen library door. The tape drive canister cooling fans draw airsupplied from the air curtain. The tape drive canisters exhaust airtoward the back of the frame. The airflow in the air curtain may tend toform a recirculating loop through the tape drive canisters and backthrough the air curtain canister(s) above the tape drive canisters. Therecirculating air tends to increase in temperature over time due to heatgenerated in the drive electronics in addition to the fan motion. Therecirculating air is preferably selectively mixed with relatively coolerair in order to create air that is the proper temperature and/orhumidity level to be exhausted as the air curtain. Because of the shapeof the airflow in the air curtain, the airflow in the air curtaininfrequently mixes with the warmer outside air. If a library door is inan open configuration, the warm, moist outside air is not substantiallydrawn into the tape drive canister even though the tape drive canistercooling fans continue to operate normally.

The front door of the library may be fully opened immediately after theair curtain canister fans turn on and the air curtain flows when the aircurtain canisters are in the recirculation mode. The air curtain allowsfor faster access to the library because there is no need to wait forthe internal temperature of the tape drive canisters to increasesufficiently before opening the library door.

Additionally, the tape drive canisters do not periodically draw inpotentially hazardous outside air which otherwise occurs in absence ofthe air curtain when the tape drive canister cooling fans turn on toprotect the drive internal electronics from overheating.

The tape drive internal electronics do not suffer from repeated thermalcycling in a recirculation mode, as they do in a conventionalself-protect mode without an air curtain. Thermal cycling occurs whenthe tape drive internal electronics are operating to near-overheatingconditions every few minutes whenever the tape drive canister coolingfans are turned from on to off and vice versa in a self-protect mode.Thermal cycling causes internal stress, e.g. corrosion, on the solderjoints and/or other mechanical elements of the electronics. Highoperating temperatures reduce the life of the tape drive internalelectronics. The recirculation mode prevents the occurrence of thermalcycling and improves the life and reliability of the tape drive internalelectronics.

FIG. 17 illustrates a partial cross-sectional side view of a storageframe 1500 of the data storage library 1000 of FIG. 10 according to oneapproach. As an option, the present storage frame 1500 of the datastorage library 1000 of FIG. 10 may be implemented in conjunction withfeatures from any other approach listed herein, such as those describedwith reference to the other FIGS. Of course, however, such a storageframe 1500 and others presented herein may be used in variousapplications and/or in permutations which may or may not be specificallydescribed in the illustrative configurations listed herein. Further, thestorage frame 1500 presented herein may be used in any desiredenvironment.

FIG. 17 illustrates a configuration of a data storage library which maycomprise an array of drive slots each configured to receive a datastorage drive therein, and a plurality of air curtain canisters 1200positioned laterally in the array of drive slots for creating an aircurtain across a front of the remaining drive slots in the array. Eachair curtain canister may comprise a housing having a form factorapproximating an exterior of a data storage drive, a fan for creating anairflow in the housing, and a nozzle for directing the airflow exitingthe housing in a predefined trajectory for creating the air curtain.Exemplary air curtain canisters are described in reference to FIGS.12A-14B above.

FIG. 17 further illustrates an exemplary airflow in a data storagelibrary created by an air curtain canister coupled to a source of coolerair (not shown), e.g., providing cooler air from the top panel of thestorage frame. Paneling, ducting, and/or any other type of barrier maybe present at the rear of the drives to direct the circulating air backto the air curtain canister 1200. In the example shown, a panel 1502isolates the air exiting the drives from the remaining areas of thestorage frame and directs it to the air curtain canister 1200. Moreover,paneling, ducting, and/or any other known type of barrier may be presentto direct the cooler air to the air curtain canister 1200. In theexample shown, the cooler air enters through the top panel of thestorage frame, as indicated by the bend arrow originating near the toppanel of the storage frame.

The air curtain canister may operate in a recirculation mode and/or acontinuous mode, according to various approaches. In a recirculationmode, the air curtain canister fans are turned on in response to atrigger condition, e.g., as described above with reference to FIG. 16.

In a continuous mode, the air curtain canister fans operate continuouslyuntil the air curtain canister is instructed otherwise. For example, ina continuous mode, the fan(s) in an air curtain canister remain turnedon indefinitely, and in the approach shown in FIG. 17, the inlet(s) tothe air curtain canister are controlled so that a relatively warmer airstream and a relatively cooler air stream are selectively mixed in theair curtain canister such that the air curtain airflow is asubstantially constant and desired temperature and/or relative humidity.The air curtain canister may comprise one or more valves for selectivelycontrolling an amount of relatively cooler air mixed with the air in theairflow which is drawn into the air curtain canisters from the rear ofthe array of drive slots. In a continuous mode, all of the tape drivecanisters may have a substantially known and uniform inlet environmentalcondition so that variations in writing and reading conditions betweentape drives in the same library are minimized.

In the exemplary continuous mode shown, relatively cooler air isselectively added to air being moved by at least some of the air curtaincanisters for cooling the air based on at least one factor. Factors tobe considered for determining whether to selectively add relativelycooler air include temperature sensor readings and/or humidity sensorreadings. The temperature and/or the relative humidity of the inlet airto the drive canisters may be optimized so that data may be written andread to the tape media at substantially stable and optimal conditions.

In one configuration, an air curtain canister for continuous modeoperation may have a different air inlet physical design than an aircurtain canister for recirculation mode operation. The continuous modeair curtain canister may include similar housing dimensions andfeatures. The continuous mode air curtain canister may include inlets todraw air from multiple sources of temperature and/or humidity controlledair. The inlets draw air from multiple sources of temperature and/orhumidity controlled air in order to mix the air before exhausting theair through the nozzle at the front of the air curtain canister.

A continuous mode air curtain canister may comprise one or moreadditional cold air inlets at the front of the air curtain canister. Theadditional cold air inlets may be directed upward. The additional coldair inlets may be located near the opening where relatively cooler airfrom the integrated cooling air conditioner directs relatively coolerair into the accessor aisle. The cold air inlet allows relatively coolerair to enter the air curtain canister and flow through an internalmixing chamber (e.g. the mixing chamber).

In a preferred approach, each fan in the continuous mode air curtaincanister may draw air from different plenums in the frame (e.g. oneplenum being a relatively warmer air source and another plenum being arelatively cooler air source). The sensors in the air curtain canisterssense the temperature and/or relative humidity states of the inlet airand/or the mixed air. The air curtain canisters adjust the settings ofthe fan(s) and/or valve(s) according to the temperature and/or humiditystates in order to control the temperature and/or relative humidity ofthe exhausted air of the air curtain.

In one example, the continuous mode operation air curtain canister maycomprise at least two fans. The relatively cooler air is drawn into thecanister by turning on one or more of the internal fans. The relativelycooler air may then be mixed with relatively warmer air being drawn intothe rear of the air curtain canister by another internal fan. The mixedintermediate temperature air is exhausted through the nozzle into theair curtain airflow. The air curtain flows vertically downward towardthe tape drive canisters below the air curtain canister.

In one approach, a method for controlling air curtain canisters, e.g.,in the continuous mode and/or recirculation mode, is provided. Themethod may be performed in accordance with the present invention in anyof the environments disclosed herein. Of course, more or less operationsthat those specifically described in herein may be included in themethod, as would be understood by one of skill in the art upon readingthe present description.

Each of the steps of the method may be performed by any suitablecomponent of the operating environment. For example, in various aspects,the method may be partially or entirely performed by a computer, or someother device having one or more processors therein. The processor, e.g.,processing circuit(s), chip(s), and/or module(s) implemented in hardwareand/or software, and preferably having at least one hardware componentmay be utilized in any device to perform one or more steps of themethod. Illustrative processors include, but are not limited to, acentral processing unit (CPU), an application specific integratedcircuit (ASIC), a field programmable gate array (FPGA), etc.,combinations thereof, or any other suitable computing device known inthe art.

The method includes selectively instructing air curtain canisters in adata storage library to create an air curtain across a front of an arrayof drive slots. Exemplary air curtain canisters are described inreference to FIGS. 12A-14B above.

Selectively instructing air curtain canisters in a data storage librarymay include instructing one or more air curtain canisters in the datastorage library to turn on one or more fans in the air curtaincanisters. Each air curtain canister may comprise one or more fans forcreating an airflow. In one configuration, the fan may comprise one ormore blade fans, centrifugal blowers, positive displacement blowers,squirrel cage blowers, other blowers, or any other type of apparatus forcreating a current of air known in the art.

In one configuration, the fans may be individually controllable suchthat one or more of the fans may be turned off and on, the speed of thefans may be adjusted, a second fan may start only when a triggercondition occurs as a boosting effect, one or more of the fans arecapable of reversing directions, etc.

In one approach, the air curtain canisters draw air from a rear of thearray of drive slots. Air from the rear of the array of drive slotstypically comprises air that has passed through the tape drive canisterswhich is warmed via the internal electronics, the movement of the fans,etc.

Another operation of the method comprises mixing relatively cooler airwith air being moved through the air curtain canisters for cooling theair. One or more fans in the air curtain canisters may be used toselectively mix the relatively cooler air with air being moved throughthe air curtain. Again, the one or more fans may be individuallycontrollable. Mixing relatively cooler air with air being moved throughthe air curtain canisters may include turning on a first fan, turning ona second fan, increasing the speed for one or more of the fans,instructing a cold air supply system to send relatively cooler air tothe air curtain canisters, etc.

In one configuration, the air curtain canisters may each comprise avalve for selectively controlling an amount of the relatively cooler airmixed with the air in the airflow which is drawn into the air curtaincanister from the rear of the array of drive slots. The valve may be aglobe valve, a gate valve, a ball valve, a butterfly valve, a plugvalve, a check valve, a diaphragm valve, a needle valve, a pinch valve,or any other valve known in the art. In one approach, the air curtaincanister may comprise any combination of valves and/or fans forselectively controlling an amount of relatively cooler air mixed withthe air in the airflow which is drawn into the air curtain canister fromthe rear of the array of drive slots.

In one approach, the method may include heating air being moved by theair curtain canisters. The air curtain canisters and/or the data storagelibrary may comprise a heater for heating air in the airflow. The heatermay comprise one or more nichrome wire coils, ionic heating elements,tourmaline heating elements, ceramic heating elements, porcelain heatingelements, infrared heating elements, titanium heating elements, or anyother heating elements known in the art. The heater(s) may be used toheat air in the airflow in order to heat sensitive components of thetape drive canister to above the dew point of the outside air to preventcondensation.

In one approach, the air curtain position is between a travel path of arobotic accessor and the front of the array of drive slots. The datastorage library may comprise a robotic accessor configured to move datastorage cartridges between storage slots and drives in the drive slots.The robotic accessor may be of the type as described above in FIGS. 1-8.In one approach, the air curtain is thin enough to be effective even ifan accessor is located in front of the drives being protected by the aircurtain.

In one approach, the air curtain across a front of an array of driveslots in the data storage library may comprise a volume of air enteringthe full air curtain which is at least as great as the volume of air thedrives in the drive slots cumulatively draw. The volume of air enteringthe full air curtain may be measured per unit time and the volume of airthe drives in the drive slots cumulatively draw may be measured per thesame unit of time.

In one operation of the method, the air curtain canisters are instructedto run continuously when a continuous mode is active, where the aircurtain canisters are only instructed to run in response to a triggercondition when a recirculating mode is active.

A trigger condition may include detecting opening of a front door of thedata storage library, receiving a command to run the air curtaincanisters from a user, occurrence of a specific time based on apredetermined schedule, sensing the temperature is too high based on apredefined operating temperature threshold, sensing the temperature istoo low based on a predefined operating temperature threshold, sensingthe humidity is too high based on a predefined operating humiditythreshold, and sensing the humidity is too low based on a predefinedoperating humidity thresholds, etc., e.g., as described above.

In one approach of the method, the air curtain canisters are instructedto run continuously in a continuous mode, where relatively cooler air isselectively added to air being moved by at least some of the air curtaincanisters for cooling the air based on at least one factor. Factors tobe considered for determining whether to selectively add relativelycooler air include temperature sensor readings and/or humidity sensorreadings.

FIG. 18 is a partial cross-sectional side view of a storage frame 1800of the data storage library 1000 of FIG. 10 according to one approach.As an option, the storage frame 1800 may be implemented in conjunctionwith features from any other approach listed herein, such as thosedescribed with reference to the other FIGS. Of course, however, such astorage frame 1800 and others presented herein may be used in variousapplications and/or in permutations which may or may not be specificallydescribed in the illustrative configurations listed herein. Further, thestorage frame 1800 presented herein may be used in any desiredenvironment.

FIG. 18 illustrates a configuration of a data storage library which maycomprise an array of drive slots each configured to receive a datastorage drive therein, a nozzle 1802 for creating an air curtain acrossa front of the array of drive slots and a fan 1804 for creating anairflow through the nozzle.

In one configuration, the nozzle 1802 has a downward-directed narrowopening for directing airflow in a predefined trajectory for creating anair curtain. The downward-directed narrow opening may allow a relativelyhigh volume and velocity airflow to exhaust from the air curtain suchthat the airflow creates a wide but thin “curtain” of air.

In one approach, the nozzle 1802 is positioned above the drive slots.The nozzle 1802 may be directed toward the front of the array of driveslots. The air curtain flows vertically down in front of the drive slotsbelow. The protrusion of the downward-directed narrow opening of thenozzle may be limited by the effective operation of the robotic accessorand other components in the library as described above in regard to FIG.2 and other Figures.

In one configuration, the nozzle 1802 has a width sufficient to createthe air curtain across at least two horizontally-adjacent drive slots.In another approach, the nozzle includes a plurality of sub-nozzles,each sub-nozzle creating a portion of the air curtain.

In one approach, the nozzle 1802 (e.g. nozzle, sub-nozzles, etc.) may becontrollable such that the direction of the airflow may be modified. Forexample, the angle and/or shape of the downward-directed narrow openingmay be adjustable to create a wider and/or narrower air curtain. Thenozzle may comprise one or more individually controllable baffles fordirecting the air curtain. In one approach, the nozzle comprises ventingair diverters for adjusting the angle of the airflow in order to changethe direction of the air curtain and/or to create a wider and/ornarrower air curtain.

In one configuration, the fan 1804 may comprise one or more blade fans,centrifugal blowers, positive displacement blowers, squirrel cageblowers, other blowers, or any other type of apparatus known in the artfor creating a current of air.

The data storage library may comprise one or more fans which draw airfrom a rear of the array of drive slots. The air from the rear of thearray of drive slots typically comprises air drawn through the tapedrive canisters which is warmed via the internal electronics, themovement of the fans, etc.

In one approach, the fans may be individually controllable such that oneor more of the fans may be turned off and on, the speed may be adjusted,a second fan may start only when a trigger condition occurs as aboosting effect, one or more of the fans are capable of reversingdirections, etc.

In one configuration, one or more fans may be individually controllablesuch that one or more fans may be turned off until the fan(s) areinstructed to turn on. In another approach, the one or more fans may beindividually controllable such that one or more of the fans may beturned on until one or more of the fans are instructed to turn off.

In yet another approach, a second fan may be turned off and, in responseto a trigger condition, turned on to create a boosting effect. Aboosting effect may increase the mixing of relatively cooler air withair in the airflow. A boosting effect may include turning on a secondfan to increase the velocity of the airflow in the air curtain and/orthroughout the housing.

In another approach, reversing the direction of the one or more fans mayreverse the direction of the airflow. The fans may reverse the directionof the airflow in order to adjust the intermixing between the outsideair and the air in the air curtain that is drawn into the tape drivecanisters. The direction of the fan may be reversed in response to atrigger condition.

As mentioned above, various actions (e.g. such as starting one or morefans) may occur upon detecting a trigger condition. A trigger conditionmay include detecting opening of a front door of the data storagelibrary, receiving a command to run the fan from a user, occurrence of aspecific time based on a predetermined schedule, sensing the temperatureis too high based on a predefined operating temperature threshold,sensing the temperature is too low based on a predefined operatingtemperature threshold, sensing the humidity is too high based on apredefined operating humidity threshold, and sensing the humidity is toolow based on a predefined operating humidity thresholds, etc. Thepredefined operating temperature threshold may be a temperature of theoutside air at or above which condensation could occur if the outsideair is drawn into the tape drives. The predefined operating temperaturethreshold may be above optimal temperatures for tape drive operation.The predefined operating humidity threshold may be a humidity level ofthe outside air at or above which condensation could occur if theoutside air is drawn into the tape drives. The predefined operatinghumidity threshold may be above optimal humidity levels for tape driveoperation.

In one approach, the velocity of the air in the airflow created by thefan is sufficient to create a barrier to outside air. The fan and nozzlefor directing the airflow create a velocity of airflow in the aircurtain such that the intermixing is less than 10% intermixing ofoutside air with the air drawn into the tape drives behind the aircurtain. The intermixing may be less than approximately 10%, 9%, 8%, 7%,6%, 5%, 4%, 3%, 2%, or 1% intermixing of outside air with the air drawninto the tape drives. In another approach, the intermixing may be 0%.

The data storage library may include at least one cold air inlet formixing relatively cooler air with air being moved by the fan. The coldair inlets may receive relatively cooler air for mixing with air in theairflow from one or more sources of relatively cooler air. Cold air maybe used interchangeably herein to refer to “relatively cooler air.”

In one configuration, the cold air inlet receives relatively cooler airfor mixing with air in the airflow from one or more air conditioningunits which are positioned above the fan and/or the nozzle. The airconditioning unit may be of any type known in the art. The airconditioning unit may be a CRAC unit, a central air conditioning unit, aductless mini-split air conditioning unit, a hybrid air conditioner, aHVAC system, etc.

In one configuration, the data storage library may comprise data storagedrives in at least some of the drive slots, where the data storagelibrary is configured to create a full air curtain across the entirefront of the occupied drive slots. The volume of air entering the fullair curtain may be at least as great as the volume of air the drives inthe drive slots cumulatively draw. The volume of air entering the fullair curtain may be measured per unit time and the volume of air thedrives in the drive slots cumulatively draw may be measured per the sameunit of time.

The data storage library may comprise a robotic accessor configured tomove data storage cartridges between storage slots and drives in thedrive slots, where the air curtain position is between a travel path ofthe robotic accessor and the front array of the drive slots. The roboticaccessor may be of the type as described above in FIGS. 1-8. In oneapproach, the air curtain is thin enough to be effective even if anaccessor is located in front of the drives being protected by the aircurtain.

In another approach, the data storage library comprises a door and aswitch for detecting when the door is open, where the data storagelibrary is configured to activate the fan in response to detecting thatthe door is open. Such a door and a switch for detecting when the dooris open may be any of a type known in the art.

In yet another approach, the data storage library comprises atemperature sensor for detecting a temperature in the data storagelibrary. The data storage library may be configured to activate the fanin response to detecting a temperature in a predefined range. Thetemperature sensor may be a negative temperature coefficient (NTC)thermistor, a resistance temperature detector (RTD), a thermocouple, asemiconductor-based sensor, an infrared sensor, a bimetallic device, athermometer, a change-of-state sensor, etc. The temperature sensor maybe any temperature sensor known in the art.

In another approach, the data storage library comprises a humiditysensor for detecting a humidity level in the data storage library. Thedata storage library may be configured to activate the fan in responseto detecting a humidity level in a predefined range. The humidity sensormay be a capacitive sensor, a resistive sensor, a thermally conductivesensor, etc. The humidity sensor may be any humidity sensor known in theart.

FIG. 19 illustrates a partial cross-sectional side view of a storageframe 1800 of the data storage library 1000 of FIG. 10 according to oneapproach. As an option, the storage frame 1800 may be implemented inconjunction with features from any other approach listed herein, such asthose described with reference to the other FIGS. Of course, however,such a storage frame 1800 and others presented herein may be used invarious applications and/or in permutations which may or may not bespecifically described in the illustrative configurations listed herein.Further, the storage frame 1800 presented herein may be used in anydesired environment.

FIG. 19 illustrates a configuration of a data storage library whichcomprises an array of drive slots each configured to receive a datastorage drive therein, a nozzle 1802 for creating an air curtain acrossa front of the array of drive slots, and a fan 1804 for creating anairflow through the nozzle. Paneling, ducting, and/or any other knowntype of barrier may be present at the rear of the drives to direct thecirculating air back to the air curtain. In the example shown, a panel1806 isolates the air exiting the drives from the remaining areas of thestorage frame and directs it to the air curtain.

FIG. 19 illustrates an exemplary airflow in a data storage librarycreated by an air curtain. The air curtain generator may operate in arecirculation mode and/or a continuous mode according to variousapproaches. In a continuous mode, the fans in the data storage librarycontinuously until the fan is instructed otherwise.

In a recirculation mode, one or more fans are turned on in response to atrigger condition. A trigger condition may include detecting opening ofa front door of the data storage library, receiving a command to run thefans from a user, occurrence of a specific time based on a predeterminedschedule, sensing the temperature is too high based on a predefinedoperating temperature threshold, sensing the temperature is too lowbased on a predefined operating temperature threshold, sensing thehumidity is too high based on a predefined operating humidity threshold,and sensing the humidity is too low based on a predefined operatinghumidity thresholds, etc. The predefined operating temperature thresholdmay be a temperature of the outside air at or above which condensationcould occur if the outside air is drawn into the tape drives. Thepredefined operating temperature threshold may be above optimaltemperatures for tape drive operation. The predefined operating humiditythreshold may be a humidity level of the outside air at or above whichcondensation could occur if the outside air is drawn into the tapedrives. The predefined operating humidity threshold may be above optimalhumidity levels for tape drive operation.

In the recirculation mode, the tape drive canisters do not draw air fromthe accessor aisle and/or air from outside the library coming throughthe open library door. The tape drive canister cooling fans draw airsupplied from the air curtain. The tape drive canisters exhaust airtoward the back of the frame. The airflow in the air curtain may tend toform a recirculating loop through the tape drive canisters and backthrough the fan and the nozzle. The recirculating air tends to increasein temperature over time due to heat generated in the drive electronicsin addition to the fan motion. The recirculating air is preferablyselectively mixed with relatively cooler air in order to create air thatis the proper temperature and/or humidity level to be exhausted as theair curtain. Because of the shape of the airflow in the air curtain, theairflow in the air curtain infrequently mixes with the warmer airgenerated by the drive electronics. If a library door is in an openconfiguration, the warm, moist outside air is not substantially drawninto the tape drive canister even though the tape drive canister coolingfans continue to operate normally.

The front door of the library may be fully opened immediately after theone or more fans are turned on and the air curtain flows when the fansare in the recirculation mode. The air curtain allows for faster accessto the library because there is no need to wait for the internaltemperature of the tape drive canisters to increase sufficiently beforeopening the library door.

Additionally, the tape drive canisters do not periodically draw inpotentially hazardous outside air which otherwise occurs in the absenceof the air curtain when the cooling fans in the data storage libraryturn on to protect the drive internal electronics from overheating.

The tape drive internal electronics do not suffer from repeated thermalcycling in a recirculation mode, as they do in a conventionalself-protect mode without an air curtain. Thermal cycling occurs whenthe tape drive internal electronics are operating to near-overheatingconditions every few minutes whenever the tape drive canister coolingfans are turned from on to off and vice versa in a self-protect mode.Thermal cycling causes internal stress, e.g. corrosion, on the solderjoints and/or other mechanical elements of the electronics. Highoperating temperatures reduce the life of the tape drive internalelectronics. The recirculation mode prevents the occurrence of thermalcycling and improves the life and reliability of the tape drive internalelectronics.

FIG. 20 illustrates a partial cross-sectional side view of a storageframe 1800 of the data storage library 1000 of FIG. 10 according to oneapproach. As an option, the storage frame 1800 may be implemented inconjunction with features from any other approach listed herein, such asthose described with reference to the other FIGS. Of course, however,such a storage frame 1800 and others presented herein may be used invarious applications and/or in permutations which may or may not bespecifically described in the illustrative configurations listed herein.Further, the storage frame 1800 presented herein may be used in anydesired environment.

FIG. 20 illustrates a configuration of a data storage library whichcomprises an array of drive slots each configured to receive a datastorage drive therein, a nozzle 1802 for creating an air curtain acrossa front of the array of drive slots, and a fan 1804 for creating anairflow through the nozzle.

FIG. 20 illustrates an exemplary airflow in a data storage librarycreated by fans 1804 in the data storage library coupled to a source(not shown) of cooler air providing cooler air from the top panel.Paneling, ducting, and/or any other type of barrier may be present atthe rear of the drives to direct the circulating air back to the aircurtain. In the example shown, a panel 1806 isolates the air exiting thedrives from the remaining areas of the storage frame and directs it tothe air curtain. Moreover, paneling, ducting, and/or any other knowntype of barrier may be present to direct the cooler air to the aircurtain. In the example shown, the cooler air enters through the toppanel of the storage frame, as indicated by the bend arrow originatingnear the top panel of the storage frame.

The fans may operate in a recirculation mode and/or a continuous mode,according to various approaches. In a recirculation mode, the fans areturned on in response to a trigger condition, e.g., as described abovewith reference to FIG. 19.

In a continuous mode, one or more fans operate continuously untilinstructed otherwise. For example, in a continuous mode, the fan(s)remain turned on indefinitely, and in the approach shown in FIG. 20, theinlet(s) are controlled so that a relatively warm air stream and arelatively cooler air stream are selectively mixed such that the aircurtain airflow is a substantially constant and desired temperatureand/or relative humidity.

In the continuous mode, one or more fans selectively control the mixingof relatively cooler air with air being moved by the fan(s) for coolingthe air. The relatively cooler air is selectively added to air beingmoved by the fan for cooling based on at least one factor. Factors to beconsidered for determining whether to selectively add relatively coolerair include temperature sensor readings and/or humidity sensor readings.The temperature and/or the relative humidity of the air may be optimizedso that data may be written and read to the tape media at substantiallystable and optimal conditions.

In a preferred approach of the continuous mode, each fan in the datastorage library may draw air from different plenums in the frame (e.g.one plenum being a relatively warmer air source and another plenum beinga relatively cooler air source). The sensors in the data storage librarysense the temperature and/or relative humidity states of the inlet airand/or the mixed air. The data storage library adjusts the settings ofthe fan(s) according to the temperature and/or humidity states in orderto control the temperature and/or relative humidity of the exhausted airof the air curtain.

In one approach, a method for controlling air curtain generation, e.g.,in the continuous mode and/or recirculation mode, is provided. Themethod may be performed in accordance with the present invention in anyof the environments disclosed herein. Of course, more or less operationsthat those specifically described in herein may be included in themethod, as would be understood by one of skill in the art upon readingthe present description.

Each of the steps of the method may be performed by any suitablecomponent of the operating environment. For example, in various aspects,the method may be partially or entirely performed by a computer, or someother device having one or more processors therein. The processor, e.g.,processing circuit(s), chip(s), and/or module(s) implemented in hardwareand/or software, and preferably having at least one hardware componentmay be utilized in any device to perform one or more steps of themethod. Illustrative processors include, but are not limited to, acentral processing unit (CPU), an application specific integratedcircuit (ASIC), a field programmable gate array (FPGA), etc.,combinations thereof, or any other suitable computing device known inthe art.

The method may initiate with selectively instructing a fan to create anairflow through a nozzle for creating an air curtain across a front ofan array of drive slots in a data storage library.

The data storage library may comprise one or more fans for creating anairflow. In one approach, the fan may comprise one or more blade fans,centrifugal blowers, positive displacement blowers, squirrel cageblowers, other blowers, or any other type of apparatus for creating acurrent of air known in the art.

In one approach, the fans may be individually controllable such that oneor more of the fans may be turned off and on, the speed of the fans maybe adjusted, a second fan may start only when a trigger condition occursas a boosting effect, one or more of the fans are capable of reversingdirections, etc.

In one approach, the fan draws air from a rear of the array of driveslots. Air from the rear of the array of drive slots typically comprisesair that has passed through the tape drive canisters which is warmed viathe internal electronics, the movement of the fans, etc. One or morefans in the data storage library are used for drawing air from a rear ofthe array for cooling the air.

Another operation of the method comprises mixing relatively cooler airwith air being moved by the fan for cooling the air. One or more fansmay be used to selectively mix the relatively cooler air with air beingmoved through the air curtain. Again, the one or more fans may beindividually controllable. Mixing relatively cooler air with air beingmoved by the fan may include turning on a first fan, turning on a secondfan, increasing the speed for one or more of the fans, instructing acold air supply system to send relatively cooler air to the data storagelibrary, etc.

In one configuration, the air curtain position is between a travel pathof a robotic accessor and the front of the array of drive slots. Thedata storage library may comprise a robotic accessor configured to movedata storage cartridge between storage slots and drives in the driveslots. The robotic accessor may be of the type as described above inFIGS. 1-8. In one approach, the air curtain is thin enough to beeffective even if an accessor is located in front of the drives beingprotected by the air curtain.

In one approach, the air curtain across a front of an array of driveslots in the data storage library may comprise a volume of air enteringthe full air curtain which is at least as great as the volume of air thedrives in the drive slots cumulatively draw. The volume of air enteringthe full air curtain may be measured per unit time and the volume of airthe drives in the drive slots cumulatively draw may be measured per thesame unit of time.

In one operation of the method, the fan is instructed to runcontinuously when a continuous mode is active, where the fan is onlyinstructed to run in response to a trigger condition when arecirculating mode is active.

A trigger condition may include detecting opening of a front door of thedata storage library, receiving a command to run the fan from a user,occurrence of a specific time based on a predetermined schedule, sensingthe temperature is too high based on a predefined operating temperaturethreshold, sensing the temperature is too low based on a predefinedoperating temperature threshold, sensing the humidity is too high basedon a predefined operating humidity threshold, and sensing the humidityis too low based on a predefined operating humidity thresholds, etc.,e.g., as described above.

In one approach of the method, the fan is instructed to run continuouslyin a continuous mode, where relatively cooler air is selectively addedto air being moved by the fan for cooling the air based on at least onefactor. Factors to be considered for determining whether to selectivelyadd relatively cooler air include temperature sensor readings and/orhumidity sensor readings.

The present invention may be a system, a method, and/or a computerprogram product. The computer program product may include a computerreadable storage medium (or media) having computer readable programinstructions thereon for causing a processor to carry out aspects of thepresent invention.

The computer readable storage medium can be a tangible device that canretain and store instructions for use by an instruction executiondevice. The computer readable storage medium may be, for example, but isnot limited to, an electronic storage device, a magnetic storage device,an optical storage device, an electromagnetic storage device, asemiconductor storage device, or any suitable combination of theforegoing. A non-exhaustive list of more specific examples of thecomputer readable storage medium includes the following: a portablecomputer diskette, a hard disk, a random access memory (RAM), aread-only memory (ROM), an erasable programmable read-only memory (EPROMor Flash memory), a static random access memory (SRAM), a portablecompact disc read-only memory (CD-ROM), a digital versatile disk (DVD),a memory stick, a floppy disk, a mechanically encoded device such aspunch-cards or raised structures in a groove having instructionsrecorded thereon, and any suitable combination of the foregoing. Acomputer readable storage medium, as used herein, is not to be construedas being transitory signals per se, such as radio waves or other freelypropagating electromagnetic waves, electromagnetic waves propagatingthrough a waveguide or other transmission media (e.g., light pulsespassing through a fiber-optic cable), or electrical signals transmittedthrough a wire.

Computer readable program instructions described herein can bedownloaded to respective computing/processing devices from a computerreadable storage medium or to an external computer or external storagedevice via a network, for example, the Internet, a local area network, awide area network and/or a wireless network. The network may comprisecopper transmission cables, optical transmission fibers, wirelesstransmission, routers, firewalls, switches, gateway computers and/oredge servers. A network adapter card or network interface in eachcomputing/processing device receives computer readable programinstructions from the network and forwards the computer readable programinstructions for storage in a computer readable storage medium withinthe respective computing/processing device.

Computer readable program instructions for carrying out operations ofthe present invention may be assembler instructions,instruction-set-architecture (ISA) instructions, machine instructions,machine dependent instructions, microcode, firmware instructions,state-setting data, or either source code or object code written in anycombination of one or more programming languages, including an objectoriented programming language such as Smalltalk, C++ or the like, andconventional procedural programming languages, such as the “C”programming language or similar programming languages. The computerreadable program instructions may execute entirely on the user'scomputer, partly on the user's computer, as a stand-alone softwarepackage, partly on the user's computer and partly on a remote computeror entirely on the remote computer or server. In the latter scenario,the remote computer may be connected to the user's computer through anytype of network, including a local area network (LAN) or a wide areanetwork (WAN), or the connection may be made to an external computer(for example, through the Internet using an Internet Service Provider).In some embodiments, electronic circuitry including, for example,programmable logic circuitry, field-programmable gate arrays (FPGA), orprogrammable logic arrays (PLA) may execute the computer readableprogram instructions by utilizing state information of the computerreadable program instructions to personalize the electronic circuitry,in order to perform aspects of the present invention.

Aspects of the present invention are described herein with reference toflowchart illustrations and/or block diagrams of methods, apparatus(systems), and computer program products according to embodiments of theinvention. It will be understood that each block of the flowchartillustrations and/or block diagrams, and combinations of blocks in theflowchart illustrations and/or block diagrams, can be implemented bycomputer readable program instructions.

These computer readable program instructions may be provided to aprocessor of a general purpose computer, special purpose computer, orother programmable data processing apparatus to produce a machine, suchthat the instructions, which execute via the processor of the computeror other programmable data processing apparatus, create means forimplementing the functions/acts specified in the flowchart and/or blockdiagram block or blocks. These computer readable program instructionsmay also be stored in a computer readable storage medium that can directa computer, a programmable data processing apparatus, and/or otherdevices to function in a particular manner, such that the computerreadable storage medium having instructions stored therein comprises anarticle of manufacture including instructions which implement aspects ofthe function/act specified in the flowchart and/or block diagram blockor blocks.

The computer readable program instructions may also be loaded onto acomputer, other programmable data processing apparatus, or other deviceto cause a series of operational steps to be performed on the computer,other programmable apparatus or other device to produce a computerimplemented process, such that the instructions which execute on thecomputer, other programmable apparatus, or other device implement thefunctions/acts specified in the flowchart and/or block diagram block orblocks.

The flowchart and block diagrams in the Figures illustrate thearchitecture, functionality, and operation of possible implementationsof systems, methods, and computer program products according to variousembodiments of the present invention. In this regard, each block in theflowchart or block diagrams may represent a module, segment, or portionof instructions, which comprises one or more executable instructions forimplementing the specified logical function(s). In some alternativeimplementations, the functions noted in the block may occur out of theorder noted in the figures. For example, two blocks shown in successionmay, in fact, be executed substantially concurrently, or the blocks maysometimes be executed in the reverse order, depending upon thefunctionality involved. It will also be noted that each block of theblock diagrams and/or flowchart illustration, and combinations of blocksin the block diagrams and/or flowchart illustration, can be implementedby special purpose hardware-based systems that perform the specifiedfunctions or acts or carry out combinations of special purpose hardwareand computer instructions.

Moreover, a system according to various embodiments may include aprocessor and logic integrated with and/or executable by the processor,the logic being configured to perform one or more of the process stepsrecited herein. By integrated with, what is meant is that the processorhas logic embedded therewith as hardware logic, such as an applicationspecific integrated circuit (ASIC), a field programmable gate array(FPGA), etc. By executable by the processor, what is meant is that thelogic is hardware logic; software logic such as firmware, part of anoperating system, part of an application program; etc., or somecombination of hardware and software logic that is accessible by theprocessor and configured to cause the processor to perform somefunctionality upon execution by the processor. Software logic may bestored on local and/or remote memory of any memory type, as known in theart. Any processor known in the art may be used, such as a softwareprocessor module and/or a hardware processor such as an ASIC, a FPGA, acentral processing unit (CPU), an integrated circuit (IC), a graphicsprocessing unit (GPU), etc.

A data processing system suitable for storing and/or executing programcode may include at least one processor, which may be or be part of acontroller, coupled directly or indirectly to memory elements through asystem bus, such as processor 400 of FIG. 4. The memory elements caninclude local memory employed during actual execution of the programcode, such as nonvolatile memory 404 of FIG. 4, bulk storage, and cachememories which provide temporary storage of at least some program codein order to reduce the number of times code must be retrieved from bulkstorage during execution.

It will be clear that the various features of the foregoing systemsand/or methodologies may be combined in any way, creating a plurality ofcombinations from the descriptions presented above.

It will be further appreciated that embodiments of the present inventionmay be provided in the form of a service deployed on behalf of acustomer to offer service on demand.

While various embodiments have been described above, it should beunderstood that they have been presented by way of example only, and notlimitation. Thus, the breadth and scope of an embodiment of the presentinvention should not be limited by any of the above-described exemplaryembodiments, but should be defined only in accordance with the followingclaims and their equivalents.

What is claimed is:
 1. A data storage library, comprising: an array ofdrive slots each configured to receive a data storage drive therein; anozzle for creating an air curtain across a front of the array of driveslots; and a fan for creating an airflow through the nozzle.
 2. The datastorage library as recited in claim 1, wherein the fan draws air from arear of the array of drive slots.
 3. The data storage library as recitedin claim 2, comprising a cold air inlet for mixing cooler air with airbeing moved by the fan.
 4. The data storage library as recited in claim2, comprising data storage drives in at least some of the drive slots,wherein the data storage library is configured to create a full aircurtain across the entire front of the occupied drive slots, wherein avolume of air entering the full air curtain is at least as great as avolume of air the drives in the drive slots cumulatively draw.
 5. Thedata storage library as recited in claim 1, comprising a roboticaccessor configured to move data storage cartridges between storageslots and drives in the drive slots, wherein the air curtain position isbetween a travel path of the robotic accessor and the front of the arrayof drive slots.
 6. The data storage library as recited in claim 1,wherein the nozzle is positioned above the drive slots.
 7. The datastorage library as recited in claim 1, wherein the nozzle includes aplurality of sub-nozzles, each sub-nozzle creating a portion of the aircurtain.
 8. The data storage library as recited in claim 1, wherein thenozzle has a width sufficient to create the air curtain across at leasttwo horizontally-adjacent drive slots.
 9. The data storage library asrecited in claim 1, comprising an air conditioning unit for providingcold air for the air curtain.
 10. The data storage library as recited inclaim 1, comprising a door and a switch for detecting when the door isopen, wherein the data storage library is configured to activate the fanin response to detecting that the door is open.
 11. The data storagelibrary as recited in claim 1, comprising a temperature sensor fordetecting a temperature in the data storage library, wherein the datastorage library is configured to activate the fan in response todetecting a temperature in a predefined range.
 12. The data storagelibrary as recited in claim 1, comprising a humidity sensor fordetecting a humidity level in the data storage library, wherein the datastorage library is configured to activate the fan in response todetecting a humidity level in a predefined range.
 13. A method,comprising: selectively instructing a fan to create an airflow through anozzle for creating an air curtain across a front of an array of driveslots in a data storage library.
 14. The method as recited in claim 13,wherein the fan draws air from a rear of the array of drive slots. 15.The method as recited in claim 13, comprising mixing cooler air with airbeing moved by the fan for cooling the air.
 16. The method as recited inclaim 13, wherein the air curtain position is between a travel path of arobotic accessor and the front of the array of drive slots.
 17. Themethod as recited in claim 13, wherein a volume of air per unit timeentering into the air curtain is at least as great as a volume of airper unit time the drives in the drive slots cumulatively draw.
 18. Themethod as recited in claim 13, wherein the fan is instructed to runcontinuously when a continuous mode is active, wherein the fan is onlyinstructed to run in response to a trigger condition when arecirculating mode is active.
 19. The method as recited in claim 13,wherein the fan is instructed to run in response to a trigger condition,wherein the trigger condition is selected from the group consisting of:detecting opening of a front door of the data storage library, receivinga command to run the fan from a user, occurrence of a specific timebased on a predetermined schedule, sensing a temperature is too highbased on a predefined operating temperature threshold, sensing thetemperature is too low based on a predefined operating temperaturethreshold, sensing a humidity is too high based on a predefinedoperating humidity threshold, and sensing the humidity is too low basedon a predefined operating humidity thresholds.
 20. The method as recitedin claim 13, wherein the fan is instructed to run continuously in acontinuous mode, wherein cooler air is selectively added to air beingmoved by the fan for cooling the air based on at least one factorselected from the group consisting of: a temperature reading of the airand a humidity reading of the air.
 21. A computer program product forinstructing a fan to create an air curtain, the computer program productcomprising a computer readable storage medium having programinstructions embodied therewith, wherein the computer readable storagemedium is not a transitory signal per se, the program instructionsexecutable by a processor to cause the processor to perform a methodcomprising: selectively instructing, by the processor, a fan to createan airflow through a nozzle for creating an air curtain across a frontof an array of drive slots in a data storage library.
 22. The computerprogram product as recited in claim 21, wherein the fan is instructed torun continuously when a continuous mode is active, wherein the fan isonly instructed to run in response to a trigger condition when arecirculating mode is active.
 23. The program product as recited inclaim 21, wherein the fan is instructed to run in response to a triggercondition, wherein the trigger condition is selected from the groupconsisting of: detecting opening of a front door of the data storagelibrary, receiving a command to run the fan from a user, occurrence of aspecific time based on a predetermined schedule, sensing a temperatureis too high based on a predefined operating temperature threshold,sensing the temperature is too low based on a predefined operatingtemperature threshold, sensing a humidity is too high based on apredefined operating humidity threshold, and sensing the humidity is toolow based on a predefined operating humidity thresholds.